Filed Pursuant to Rule 424(b)(3)
                                                    Registration No. 333-123198

PROSPECTUS

                               AGERE SYSTEMS INC.

                               70,331,696 SHARES

                              CLASS A COMMON STOCK

     The 70,331,696 shares of our Class A common stock offered by this
prospectus were originally issued by us in connection with our acquisition of
Modem-Art Ltd. All the shares of our Class A common stock offered by this
prospectus may be sold from time to time by or on behalf of certain Agere
stockholders. See "Selling Stockholders" and "Plan of Distribution." We are not
selling any of the shares offered by this prospectus and we will not receive
any of the proceeds from the sale of the shares by the selling stockholders.
The shares were originally issued in an offering exempt from the registration
requirements of the Securities Act of 1933. In connection with the acquisition
of Modem-Art Ltd., we agreed to register the shares of our Class A common stock
offered by this prospectus.

     SEE "RISK FACTORS" BEGINNING ON PAGE 1 TO READ ABOUT RISKS YOU SHOULD
CONSIDER BEFORE BUYING OUR CLASS A COMMON STOCK.

     Our Class A common stock, including the shares offered hereby, is listed
in the United States on the New York Stock Exchange under the symbol AGR.A. The
reported last sale price of the Class A common stock on the New York Stock 
Exchange on March 11, 2005 was $1.55 per share.

     Our principal executive offices are located at 1110 American Parkway NE,
Allentown, Pennsylvania 18109, and our telephone number at that location is
(610) 712-1000.

     The selling stockholders may sell all or a portion of the shares offered
hereby from time to time through public or private transactions on or off the
New York Stock Exchange, in negotiated transactions or otherwise, and at
prevailing market prices or negotiated prices, all as more fully described
under "Plan of Distribution."

     You should rely only on the information contained in this prospectus,
including the information in the documents incorporated by reference. We have
not, and no dealer or salesman has, authorized any other person to provide you
with different information. If anyone provides you with different or
inconsistent information, you should not rely on it. We are not, and no dealer
or salesman is, making an offer to sell these securities in any jurisdiction
where the offer or sale is not permitted.

     You should assume that the information appearing in this prospectus is
accurate only as of the date on the front cover of this prospectus. Our
business, financial condition, results of operations and prospects may have
changed since that date.

     THESE SECURITIES HAVE NOT BEEN APPROVED OR DISAPPROVED BY THE SECURITIES
AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION NOR HAS THE
SECURITIES AND EXCHANGE COMMISSION OR ANY STATE SECURITIES COMMISSION PASSED
UPON THE ACCURACY OR ADEQUACY OF THIS PROSPECTUS. ANY REPRESENTATION TO THE
CONTRARY IS A CRIMINAL OFFENSE.





The date of this prospectus is March 14, 2005.





                               TABLE OF CONTENTS

                                                                           Page
                                                                           ----



FORWARD-LOOKING STATEMENTS....................................................1
RISK FACTORS..................................................................1
THE COMPANY...................................................................7
RECENT DEVELOPMENTS...........................................................7
USE OF PROCEEDS...............................................................8
SELLING STOCKHOLDERS..........................................................8
PLAN OF DISTRIBUTION.........................................................10
LEGAL MATTERS................................................................12
EXPERTS......................................................................12
AVAILABLE INFORMATION........................................................13
INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE..............................13










                           FORWARD-LOOKING STATEMENTS

     This prospectus contains forward-looking statements that are based on
current expectations, estimates, forecasts and projections about the industry
in which we operate and management's beliefs and assumptions. Words such as
"expects," "anticipates," "intends," "plans," "believes," "seeks," "estimates,"
variations of such words and similar expressions are intended to identify such
forward-looking statements. These statements are not guarantees of future
performance and involve risks, uncertainties and assumptions which are
difficult to predict. Therefore, actual outcomes and results may differ
materially from what is expressed or forecasted in such forward-looking
statements. Except as required under the federal securities laws and the rules
and regulations of the Securities and Exchange Commission, we do not have any
intention or obligation to update publicly any forward-looking statements after
we distribute this prospectus, whether as a result of new information, future
events or otherwise.

                                  RISK FACTORS

     The purchase of our common stock involves investment risks. You should
carefully consider the following risk factors, as well as the information under
the heading "Forward-Looking Statements," together with the other information
in this prospectus, before purchasing any of the shares. If any of the
following risks actually occurs, our business, financial condition or results
of operations could be materially adversely affected.

Because our sales are concentrated on a limited number of key customers, our
revenue may materially decline if one or more of our key customers do not
continue to purchase our existing and new products in significant quantities.

     Our customer base is highly concentrated. Our top 10 end-customers
accounted for approximately 65% of our revenue in fiscal 2004. If any one of
our key customers decides to purchase significantly less from us or to
terminate its relationship with us, our revenue may materially decline. Because
our strategy has generally been to develop long-term relationships with a few
key customers in the product areas in which we focus and we have a long product
design and development cycle for most of our products, we may be unable to
replace these customers quickly or at all. We could lose our key customers or
significant sales to our key customers because of factors beyond our control,
such as a significant disruption in our customers' businesses generally or in a
specific product line.

If we fail to keep pace with technological advances in our industry or if we
pursue technologies that do not become commercially accepted, customers may not
buy our products and our results of operations may be adversely affected.

     The demand for our products can change quickly and in ways we may not
anticipate because our industry is generally characterized by:

     o    rapid, and sometimes disruptive, technological developments;

     o    evolving industry standards;

     o    changes in customer requirements;

     o    limited ability to accurately forecast future customer orders;

     o    frequent new product introductions and enhancements; and

     o    short product life cycles with declining prices over the life cycle
          of the product.

     If we fail to make sufficient investments in research and development
programs in order to develop new and enhanced products and solutions, or if we
focus on technologies that do not become widely adopted, new technologies could
render our current and planned products obsolete, resulting in the need to
change the focus of our research and development and product strategies and
disrupting our business significantly.





The integrated circuit industry is intensely competitive, and our failure to
compete effectively could result in reduced revenue.

     The market for integrated circuits is intensely competitive and subject to
rapid and disruptive technological change. We expect the intensity of
competition to continue to increase as existing competitors enhance and expand
their product offerings and as new participants enter the market. Increased
competition may result in price reductions, reduced gross margins and loss of
market share. We may not be able to compete successfully against existing or
future competitors, which may result in reduced revenue.

     The size and number of our competitors vary across our product areas, as
do the resources we have allocated to the segments we target. Therefore, many
of our competitors have greater financial, personnel, production capacity and
other resources than we have in a particular market segment or overall.
Competitors with greater financial resources may be able to offer lower prices,
additional products or services or other incentives that we cannot match or
offer. These competitors may be in a stronger position to respond quickly to
new technologies and may be able to undertake more extensive marketing
campaigns. They also may adopt more aggressive pricing policies and make more
attractive offers to potential customers, employees and strategic partners.
These competitors may make strategic acquisitions or establish cooperative
relationships among themselves or with third parties to increase their ability
to gain market share.

     Further, some of our competitors are currently selling commercial
quantities of products that we are sampling to our customers, that are still in
the initial stages of development or that we may develop in the future. By
being able to offer these products in commercial quantities before we do, our
competitors can establish significant market share, acquire design wins in
customer equipment programs and create a market position that we may be unable
to overcome once we have completed development and testing of that product.

Our revenue and operating results may fluctuate because we expect to derive
most of our revenue from semiconductor devices and the integrated circuits
industry is highly cyclical, and because of other characteristics of our
business, and these fluctuations may cause our stock price to fall.

     We expect to derive most of our revenue from the sale of integrated
circuits. Because the integrated circuits market segment is highly cyclical, we
may experience declines in our revenue that are primarily related to industry
conditions and not our products. This industry has experienced significant
downturns, often in connection with, or in anticipation of, excess
manufacturing capacity worldwide, maturing product cycles and declines in
general economic conditions.

     We focus primarily on winning competitive selection processes to develop
products for use in our customers' equipment. These selection processes can be
lengthy. After winning and beginning a product design for a customer, that
customer may not begin volume production of their equipment for a period of up
to two years, if at all. Due to this lengthy design and development cycle, we
may experience delays from the time we begin incurring expenses until the time
we generate revenue from our products. We have no assurances that our customers
will ultimately market and sell their equipment or that such efforts by our
customers will be successful. Thus, we may never generate any revenue from our
products after incurring significant design and development expenditures.

     If we are not selected by a customer to provide a product, we may
experience significantly lower revenue later, as compared to prior periods with
more revenue from earlier design wins. In addition, sales of our products for
specific customer projects often begin and end abruptly, so revenue may
increase rapidly and later decrease just as quickly. The relative timing of the
beginning and end of our sales and design processes can make our revenues less
predictable.

     Fluctuations in our revenue or operating results could cause our stock
price to decline, even if our results meet expectations. Further, stock prices
in our industry have recently been highly volatile for reasons that sometimes
are unrelated to the performance of the companies in the industry. These broad
fluctuations could adversely affect our stock price.



                                       2


If we do not achieve adequate manufacturing utilization, yields or volumes or
sufficient product reliability, our gross margins will be reduced.

     Because the manufacturing costs at our owned and joint venture
manufacturing facilities are relatively fixed, efficient utilization of
manufacturing facilities and manufacturing yields are critical to our results
of operations. If we do not experience adequate utilization of our
manufacturing facilities, our results of operations may be adversely affected.
In addition, we often must pay to reserve capacity at third-party
manufacturers. If we overestimate demand for our products, we may have to pay
for capacity that we do not use, and our results of operations may be adversely
affected.

     The manufacture of our products involves highly complex and precise
processes, requiring production in highly controlled and clean environments.
Changes in our manufacturing processes or those of our suppliers or
contractors, or the inadvertent use of defective or contaminated materials,
could significantly reduce our manufacturing yields and product reliability.
Lower than expected manufacturing yields could adversely affect our results of
operations and delay product shipments.

Because we are subject to order and shipment uncertainties, any significant
cancellations or deferrals could cause our revenue to decline or fluctuate.

     We generally sell products pursuant to purchase orders that customers may
cancel or defer on short notice without incurring a significant penalty.
Cancellations or deferrals could cause us to hold excess inventory, which could
adversely affect our results of operations. If a customer cancels or defers
product shipments, we may incur unanticipated reductions or delays in our
revenue. If a customer refuses to accept shipped products or does not pay for
these products in a timely manner, we could incur significant charges against
our income, which could materially and adversely affect our results of
operations.

A joint venture and third parties manufacture a majority of our products for
us. If these suppliers are unable to fill our orders on a timely and reliable
basis, our revenue may be adversely affected.

     We currently manufacture our integrated circuits through a combination of
internal capability, a joint venture and external sourcing with contract
manufacturers. The integrated circuit manufacturing industry has a history of
developing new manufacturing processes. We believe that the costs associated
with implementing new processes, including acquiring the necessary equipment
and building appropriate facilities, are increasing with each generation of
manufacturing processes. Because we do not want to make the financial
investments necessary for future processes, we plan to rely on third-party
contract manufacturers to make integrated circuits for us using any
manufacturing processes that we do not currently use internally. We plan to
discontinue operations at our Orlando, Florida manufacturing facility by the
end of December 2005, unless a sale of the facility can be arranged. Once we
are no longer operating that facility, we expect that a joint venture and
external manufacturing sources will manufacture all of our integrated circuits.
To the extent we rely on joint ventures and third-party manufacturing
relationships, we face the following risks:

     o    that they may not be able to develop manufacturing methods
          appropriate for our products;

     o    that manufacturing costs will be higher than planned;

     o    that reliability of our products will decline;

     o    that they may be unwilling to devote adequate capacity to produce our
          products;

     o    that they may not be able to maintain continuing relationships with
          our suppliers; and

     o    that we may have reduced control over delivery schedules and costs of
          our products.

     If any of these risks were to be realized, we could experience an
interruption in supply or an increase in costs, which could adversely affect
our results of operations.



                                       3


     In the event of an increase in demand, failure to increase our
manufacturing volumes or obtain capabilities from third parties may result in
our not being able to meet customer demand for our products, which could hurt
our relationships with our customers and result in our recording lower revenues
than would be the case if we had greater manufacturing capacity.

Because many of our current and planned products are highly complex, they may
contain defects or errors that are detected only after deployment in
commercial applications, and if this occurs, it could harm our reputation and
result in reduced revenues or increased expenses.

     Our products are highly complex and may contain undetected defects, errors
or failures. These products can only be fully tested when deployed in
commercial applications and other equipment. Consequently, our customers may
discover errors after the products have been deployed. The occurrence of any
defects, errors or failures could result in:

     o    cancellation of orders;

     o    product returns, repairs or replacements;

     o    diversion of our resources;

     o    legal actions by our customers or our customers' end-users;

     o    increased insurance costs; and

     o    other losses to us or to our customers or end-users.

     Any of these occurrences could also result in the loss of or delay in
market acceptance of our products and loss of sales, which would harm our
business and adversely affect our results of operations. We have from time to
time experienced defects in our products and expect to experience defects in
the future. Because the trend in our industry is moving toward even more
complex products in the future, this risk will intensify over time and may
result in increased expenses.

We are expanding, and may seek in the future to expand, into new areas, and if
we are not successful, our results of operations may be adversely affected.

     We are currently developing products in new areas, including high-speed
networking and consumer electronics. We may seek to expand into additional
areas in the future. We may expand through internal development efforts,
through acquisitions of companies or technologies, or a combination of these
methods.

     Our efforts may not result in sales that are sufficient for us to recoup
our investment, and we may experience higher costs than we anticipated. For
example, we may not be able to manufacture our products at a competitive cost,
may need to rely on new suppliers or may find that the development efforts are
more costly or timing consuming than we had anticipated. Our products may
support protocols that are not widely adopted. Where we choose to develop
capabilities by acquiring another company, we may not be able to integrate the
other company successfully into our operations, which may mean that we have
difficulty retaining employees from the acquired company or integrating its
technology into our products. We may have difficulties entering markets where
competitors have strong market positions.

We are upgrading our enterprise financial management system, and it is
possible that we may have a defect in the design of the system that may result
in the generation of incorrect financial information, an adverse impact on the
processing of customer orders or some other adverse impact on our business.

     We have an enterprise-wide computer system that we use to control
activities such as the processing of customer orders and accounts, the
generation of financial data used in the preparation of financial statements
and the handling of employee expense and payroll information. The system is
extremely complex because of the wide range 



                                       4


of processes that it integrates. In fiscal 2006, we expect to upgrade the
system and expand its capabilities. Because of the complex nature of the
system, it is possible that we will have a flaw in our design of the upgrade
that has an adverse impact on our business. While we intend to test the system
before implementing the upgrade, we cannot assure you that our testing would
uncover every defect in the design or implementation of the upgrade that might
be made. If such a defect did exist in the system after the upgrade, it could
have a significant impact on how we conduct our business and we may not be able
to mitigate that impact through other actions.

A widespread outbreak of an illness or other health issue could negatively
affect our manufacturing, assembly and test, design or other operations,
making it more difficult and expensive to meet our obligations to our
customers, and could result in reduced demand from our customers.

     A widespread outbreak of an illness such as severe acute respiratory
syndrome, or SARS, or avian influenza, or bird flu, could adversely affect our
operations as well as demand from our customers. A number of countries in the
Asia/Pacific region have experienced outbreaks of SARS. As a result of such an
outbreak, businesses can be shut down temporarily and individuals can become
ill or quarantined. We have manufacturing and back-office operations in
Singapore, assembly and test and back-office operations in Thailand and design
operations in China, countries where outbreaks of SARS have occurred. If our
operations are curtailed because of health issues, we may need to seek
alternate sources of supply for manufacturing or other services and alternate
sources can be more expensive. Alternate sources may not be available or may
result in delays in shipments to our customers, each of which would affect our
results of operations. In addition, a curtailment of our design operations
could result in delays in the development of new products. If our customers'
businesses are affected by health issues, they might delay or reduce purchases
from us, which could adversely affect our results of operations.

We have relatively high gross margin on the revenue we derive from the
licensing of our intellectual property, and a decline in this revenue would
have a greater impact on our net income than a decline in revenue from the
sale of our integrated circuits products.

     The revenue we generate from the licensing of our intellectual property
has a higher gross margin compared to the revenue we generate from the sale of
our integrated circuits products. Although we have derived less than 8% of our
total revenue in recent years from the licensing of intellectual property, a
decline in this licensing revenue would have a greater impact on our
profitability than a similar decline in revenues from the sale of our
integrated circuits products.

If our customers do not qualify our products or manufacturing lines or the
manufacturing lines of our third-party suppliers for volume shipments, our
results of operations may be adversely affected.

     Some customers will not purchase any of our products, other than limited
numbers of evaluation units, until they qualify the manufacturing line for the
product. We may not always be able to satisfy the qualifications. Delays in
qualification may cause a customer to discontinue use of our products and
result in a significant loss of revenue.

We conduct a significant amount of our sales activity and manufacturing
efforts outside the United States, which subjects us to additional business
risks and may adversely affect our results of operations due to increased
costs.

     In fiscal 2004, we derived approximately 83% of our revenue from sales of
our products shipped to locations outside the United States. We also
manufacture a significant portion of our products outside the United States and
are dependent on non-U.S. suppliers for many of our parts. We intend to
continue to pursue growth opportunities in both sales and manufacturing outside
the United States. Operations outside the United States are subject to a number
of risks and potential costs, which could adversely affect our revenue and
results of operations, including:

     o    our brand may not be recognized locally, which may cause us to spend
          significant amounts of time and money to build a brand identity;

     o    unexpected changes in regulatory requirements;



                                       5


     o    inadequate protection of intellectual property in some countries
          outside of the United States;

     o    currency exchange rate fluctuations;

     o    international trade disputes;

     o    political and economic instability; and

     o    disruptions in international air transport systems.

We are subject to environmental, health and safety laws, which could increase
our costs and restrict our operations in the future.

     We are subject to a variety of laws relating to the use, disposal,
clean-up of, and human exposure to, hazardous chemicals. Any failure by us to
comply with present and future environmental, health and safety requirements
could subject us to future liabilities or the suspension of production. In
addition, compliance with these or future laws could restrict our ability to
expand our facilities or require us to acquire costly pollution control
equipment, incur other significant expenses or modify our manufacturing
processes. If additional contaminants are discovered or additional cleanup
obligations are imposed at these or other sites, we could be adversely
affected.

We may be subject to intellectual property litigation and infringement claims,
which could cause us to incur significant expenses or prevent us from selling
our products. If we are unable to protect our intellectual property rights,
our business and prospects may be harmed.

     Like other companies in the semiconductor industry, we are frequently
involved in litigation regarding patent and other intellectual property rights.
From time to time, we receive notices from third-parties of potential
infringement and receive claims of potential infringement when we attempt to
license our intellectual property to others. Defending these claims could be
costly and time consuming and would divert the attention of management and key
personnel from other business issues. The complexity of the technology involved
and the uncertainty of intellectual property litigation increase these risks.
Claims of intellectual property infringement also might require us to enter
into costly royalty or license agreements. However, we may be unable to obtain
royalty or license agreements on terms acceptable to us or at all. In addition,
third-parties may attempt to appropriate the confidential information and
proprietary technologies and processes used in our business, which we may be
unable to prevent and which would harm our business and prospects.

If we fail to attract, hire and retain qualified personnel, we may not be able
to develop, market or sell our products or successfully manage our business.

     In some of our fields of operation, there are only a limited number of
people in the job market who possess the requisite skills. In the past we have
experienced difficulty in identifying and hiring sufficient numbers of
qualified engineers in parts of our business as well as in retaining employees.
The loss of the services of any key personnel or our inability to hire new
personnel with the requisite skills could restrict our ability to develop new
products or enhance existing products in a timely manner, sell products to our
customers or manage our business effectively.

Because of differences in voting power and liquidity between our Class A
common stock and Class B common stock, the market price of the Class A common
stock may be different from the market price of the Class B common stock.

     Our Class B common stock has greater voting power per share for the
election and removal of directors than our Class A common stock, and, as a
result, some investors may prefer the Class B common stock as a means of
investing in our company. The greater potential voting power may cause the
Class B common stock to trade at a higher market price than the Class A common
stock. On the other hand, the Class A common stock has historically had a
higher daily trading volume than the Class B common stock. As a result, the
Class A common stock may be 



                                       6


more liquid than the Class B common stock and more attractive to investors,
which may cause the price of the Class A common stock to be higher than the
price of the Class B common stock.

The development and evolution of markets for our integrated circuits are
dependent on factors over which we have no control. For example, if our
customers adopt new or competing industry standards with which our products
are not compatible or fail to adopt standards with which our products are
compatible, our existing products would become less desirable to our customers
and our sales would suffer.

     The emergence of markets for our integrated circuits is affected by a
variety of factors beyond our control. In particular, our products are designed
to conform to current specific industry standards. Our customers may not adopt
or continue to follow these standards, which would make our products less
desirable to our customers and reduce our sales. Also, competing standards may
emerge that are preferred by our customers, which could also reduce our sales
and require us to make significant expenditures to develop new products. To the
extent that we are not able to effectively and expeditiously adapt to new
standards, our business will suffer.

Class action litigation due to stock price volatility or other factors could
cause us to incur substantial costs and divert our management's attention and
resources.

     In the past, securities class action litigation often has been brought
against a company following periods of volatility in the market price of its
securities. Companies in the integrated circuit industry and other technology
industries are particularly vulnerable to this kind of litigation due to the
high volatility of their stock prices. Accordingly, we may in the future be the
target of securities litigation. Any securities litigation could result in
substantial costs and could divert the attention and resources of our
management.

                                  THE COMPANY

     We design, develop, manufacture and sell integrated circuit solutions for
applications such as high-density storage, mobile wireless communications and
enterprise and telecommunications networks. These solutions form the building
blocks for a broad range of computing and communications applications. Some of
our solutions include related software and reference designs. Our customers
include manufacturers of hard disk drives, mobile phones, high-speed
communications systems and personal computers. We also generate revenue from
the licensing of intellectual property.

     Integrated circuits, or chips, are made using semiconductor wafers
imprinted with a network of electronic components. They are designed to perform
various functions such as processing electronic signals, controlling electronic
system functions and processing and storing data. Reference designs are
complete specifications for products that a customer can use to build an end
product, including components, board layouts and software. By using a reference
design, a customer can reduce the amount of product design it must perform and
the amount of time required to introduce a new product into the market.

     In fiscal 2004, we realigned our business into operating segments that
focus on four target markets: Storage, Mobility, Enterprise and Networking, and
Telecommunications. We have two reportable segments for financial reporting
purposes, Consumer Enterprise and Telecommunications. The Consumer Enterprise
segment includes the Storage, Mobility and Enterprise and Networking operating
segments. Previously, we had two market focused groups -- one that focused on
client computing and communications solutions and one that focused on
telecommunications infrastructure solutions. We also have an operations group
that manages our manufacturing and supply chain activities and information
technology systems.

     We were incorporated under the laws of the state of Delaware on August 1,
2000, as a wholly owned subsidiary of Lucent Technologies Inc. and became fully
independent from Lucent on June 1, 2002. Our principal executive offices are
located at 1110 American Parkway NE, Allentown, Pennsylvania 18109, and our
telephone number at that location is (610) 712-1000.



                                       7


                              RECENT DEVELOPMENTS

     At our annual meeting of stockholders, on February 17, 2005, our
stockholders approved, among other things, the reclassification of our Class A
common stock and Class B common stock into a new, single class of common stock.
Our stockholders also approved four, alternative proposals to effect a reverse
stock split, which would allow the board to effect a reverse stock split at one
of the following ratios: 1-for-10, 1-for-20, 1-for-30 and 1-for-40, at any time
prior to our annual meeting of stockholders in 2006. As a result of these
approvals, our board has the authority to implement either or both of the
reclassification and a reverse stock split, in its discretion, without further
action by stockholders.

                                USE OF PROCEEDS

     Agere will not receive any of the proceeds from the sale of shares by the
selling stockholders. See "Plan of Distribution."

                             SELLING STOCKHOLDERS

     The following table sets forth (1) the number of shares of our Class A
common stock owned by each of the selling stockholders as of March 8, 2005, (2)
the percentage of our Class A common stock beneficially owned by each of the
selling stockholders as of March 8, 2005 and (3) the number of shares of our
Class A common stock registered for sale hereby. No estimate can be given as to
the amount of shares that will be held by the selling stockholders after
completion of this offering because the selling stockholders may offer all or
some of the shares and because, to our knowledge, there currently are no
agreements, arrangements or understandings with respect to the sale of any of
the shares. The shares offered by this prospectus may be offered from time to
time by the selling stockholders named below.



----------------------------- --------------------- ----------------------- --------------------
                                                       Number of Shares           Percent
Selling Stockholder (1)(2)      Number of Shares     Registered for Sale
                               Beneficially Owned       Hereby (3)(4)
----------------------------- --------------------- ----------------------- --------------------
                                                                            
Yosef Kofman                       2,451,672              2,451,672                  *
----------------------------- --------------------- ----------------------- --------------------
Hagit Communications Ltd.           125,245                125,245                   *
(5)
----------------------------- --------------------- ----------------------- --------------------
Kofman Communications Ltd.(5)       486,466                486,466                   *

----------------------------- --------------------- ----------------------- --------------------
Shlomo Gadot                       2,451,672              2,451,672                  *
----------------------------- --------------------- ----------------------- --------------------
Gidron Technologies Ltd. (6)        486,466                486,466                   *
----------------------------- --------------------- ----------------------- --------------------
Noa Gadot Holding Ltd. (6)          125,245                125,245                   *
----------------------------- --------------------- ----------------------- --------------------
Amir Appel                          135,476                135,476                   *
----------------------------- --------------------- ----------------------- --------------------
Eliahou Arviv                       148,868                148,868                   *
----------------------------- --------------------- ----------------------- --------------------
Efraim Orian                        199,594                199,594                   *
----------------------------- --------------------- ----------------------- --------------------
Igor Lebedev                         39,291                 39,291                   *
----------------------------- --------------------- ----------------------- --------------------
Peretz Landau                       135,476                135,476                   *
----------------------------- --------------------- ----------------------- --------------------
Avishai Leshem                       39,398                 39,398                   *
----------------------------- --------------------- ----------------------- --------------------
Abraham Shamash                      39,398                 39,398                   *
----------------------------- --------------------- ----------------------- --------------------
Ronen Shevach                       153,269                153,269                   *
----------------------------- --------------------- ----------------------- --------------------
Avraam Ben-Zur                       90,408                 90,408                   *
----------------------------- --------------------- ----------------------- --------------------
Eyal Yair                           240,832                240,832                   *
----------------------------- --------------------- ----------------------- --------------------
Miron Rapaport                       73,732                 73,732                   *
----------------------------- --------------------- ----------------------- --------------------




                                       8




----------------------------- --------------------- ----------------------- --------------------
                                                       Number of Shares           Percent
Selling Stockholder (1)(2)      Number of Shares     Registered for Sale
                               Beneficially Owned       Hereby (3)(4)
----------------------------- --------------------- ----------------------- --------------------
                                                                            
Rafael Carmon                       442,440                442,440                   *
----------------------------- --------------------- ----------------------- --------------------
Oded Eisinger                       155,140                155,140                   *
----------------------------- --------------------- ----------------------- --------------------
Vladimir Kopilevich                 138,456                138,456                   *
----------------------------- --------------------- ----------------------- --------------------
Binyamin Arviv                      154,167                154,167                   *
----------------------------- --------------------- ----------------------- --------------------
Amnon Alchlel                        56,893                 56,893                   *
----------------------------- --------------------- ----------------------- --------------------
Degtyor Ilya                         49,219                 49,219                   *
----------------------------- --------------------- ----------------------- --------------------
Mituo Ukaji                          45,204                 45,204                   *
----------------------------- --------------------- ----------------------- --------------------
Green Aunt Ltd.                      11,526                 11,526                   *
----------------------------- --------------------- ----------------------- --------------------
ESOP Trustee (for Tzvika              2,260                  2,260                    *
Shaked)
----------------------------- --------------------- ----------------------- --------------------
ESOP Trustee (for Dror                2,829                  2,829                    *
Sfaradi)
----------------------------- --------------------- ----------------------- --------------------
Genesis Partners II, L.D.C         20,057,416             20,057,416                2.2
(7)(8)
----------------------------- --------------------- ----------------------- --------------------
Genesis Partners II                2,966,248              2,966,248                  *
(Israel) L.P. (7)(8)
----------------------------- --------------------- ----------------------- --------------------
Argoquest Holdings LLC             1,362,808              1,362,808                  *
----------------------------- --------------------- ----------------------- --------------------
Ampal (Israel) Ltd.                2,511,834              2,511,834                  *
----------------------------- --------------------- ----------------------- --------------------
Advanced Communication              519,889                519,889                   *
Solutions Ltd
----------------------------- --------------------- ----------------------- --------------------
Anat Investments LLC                281,140                281,140                   *
----------------------------- --------------------- ----------------------- --------------------
Tamir Fishman Ventures II          1,426,727              1,426,727                 1.2
(Israel) LP (9)
----------------------------- --------------------- ----------------------- --------------------
Tamir Fishman Ventures II           118,831                118,831                   *
CEO Fund LP (9)
----------------------------- --------------------- ----------------------- --------------------
Tamir Fishman Ventures II          10,695,091             10,695,091                 *
LP (9)
----------------------------- --------------------- ----------------------- --------------------
Tamir Fishman Ventures II           341,559                341,559                   *
CEO Fund (US) LP (9)
----------------------------- --------------------- ----------------------- --------------------
Tamir Fishman Ventures II          1,423,164              1,423,164                  *
(Cayman Islands) LP (9)
----------------------------- --------------------- ----------------------- --------------------
Tamir Fishman Venture              7,366,001              7,366,001                  *
Capital II Ltd. (9)
----------------------------- --------------------- ----------------------- --------------------
BancBoston Investments Inc.        2,630,485              2,630,485                  *
----------------------------- --------------------- ----------------------- --------------------
Peter Michael Grant                  11,979                 11,979                   *
----------------------------- --------------------- ----------------------- --------------------
David Almagor                        43,720                 43,720                   *
----------------------------- --------------------- ----------------------- --------------------
Avnet ASIC Israel Ltd.              241,076                241,076                   *
----------------------------- --------------------- ----------------------- --------------------
Tmura                                47,386                 47,386                   *
----------------------------- --------------------- ----------------------- --------------------
Apax Israel II L.P. (10)           8,456,819              8,456,819                  *
----------------------------- --------------------- ----------------------- --------------------
Apax Israel II (Israel)            1,157,551              1,157,551                  *
L.P. (10)
----------------------------- --------------------- ----------------------- --------------------
Apax Israel II                      106,188                106,188                   *
Entrepreneur's Club L.P. (10)
----------------------------- --------------------- ----------------------- --------------------




                                      9




----------------------------- --------------------- ----------------------- --------------------
                                                       Number of Shares           Percent
Selling Stockholder (1) (2)     Number of Shares     Registered for Sale
                               Beneficially Owned       Hereby (3)(4)
----------------------------- --------------------- ----------------------- --------------------
                                                                            
Apax Israel II Entrepreneur's        85,142                 85,142                   *
 Club (Israel) L.P. (10) 

* Less than 1%.

(1)  Except as otherwise noted, the selling stockholders have sole voting and
     investment power with respect to all shares of our Class A common stock
     shown as beneficially owned by them.
(2)  The selling stockholders may transfer some or all of the shares of our
     Class A common stock shown as beneficially owned by them to their limited
     partners or other permitted transferees in transactions that are not sales
     for the purposes of the Securities Act. This prospectus and the
     registration statement of which this prospectus is a part also cover the
     sales of such shares by these transferees. Agere will file a prospectus
     supplement if, as a result of such transfers, the transferees of any
     selling stockholder identified above own 1.0% or more of Agere's
     outstanding Class A common stock.
(3)  13,359,954 shares issued to the selling stockholders in connection with
     the acquisition of Modem-Art Ltd. are being held in escrow to satisfy
     certain obligations in case of any claims by Agere for breach of certain
     warranties provided in the purchase agreement. All or a portion of the
     shares held in escrow may be sold to satisfy such obligations, which would
     reduce the beneficial ownership of each of these selling stockholders by
     his, her or its pro rata interest in the shares held in escrow that are
     sold. The shares held in escrow are included in the amounts shown in the
     table.
(4)  This prospectus and the registration statement of which this prospectus is
     a part also covers (1) any additional shares of Class A common stock that
     become issuable in connection with the shares registered for sale hereby
     by reason of any stock dividend, stock split, recapitalization or other
     similar transaction effected without the receipt of consideration that
     results in an increase in the number of outstanding shares of our Class A
     common stock and (2) any securities issuable in connection with the shares
     registered for sale hereby by reason of the reclassification or reverse
     stock split approved by our shareholders on February 17, 2005.
(5)  Yosef Kofman has voting and investment power with respect to all shares of
     our Class A common stock shown as beneficially owned by Hagit 
     Communication Ltd. and Kofman Communication Ltd.
(6)  Shlomo Gadot has voting and investment power with respect to all shares of
     our Class A common stock shown as beneficially owned by Gidron 
     Technologies Ltd. and Noa Gadot Holding Ltd.
(7)  Eddy Shalev and Eyal Kishon have shared voting and investment power over
     the portfolio securities of Genesis Partners II L.D.C and Genesis Partners
     II (Israel) L.P.
(8)  A general partner of the selling stockholder has an indirect investment in
     Agere through a fund investment it has made in Warburg Pincus Private
     Equity Fund. The general partner, CIBC Merchant Banking Division, has
     approximately 0.14% ownership of the fund.
(9)  Eldad Tamir, Daniel Fishman, Michael Elias and Shai Saul have management
     control over Tamir Fishman Ventures II LLC, which is the general partner
     of Tamir Fishman Ventures II (Israel) LP, Tamir Fishman Ventures II CEO
     Fund LP, Tamir Fishman Ventures II LP, Tamir Fishman Ventures II CEO Fund
     (US) LP, Tamir Fishman Ventures II (Cayman Islands) LP and Tamir Fishman
     Venture Capital II Ltd.
(10) Allan Barakat, Peter Englander, Ronald Cohen and Amos Goren have
     management control over Apax Israel Partners II, L.P., which is the
     general partner of Apax Israel II L.P., Apax Israel II (Israel) L.P., Apax
     Israel II Entrepreneur's Club L.P. and Apax Israel II Entrepreneur's Club
     (Israel) L.P.

     Each of the selling stockholders was a stockholder, warrant holder or
option holder of Modem-Art Ltd. immediately prior to Agere's acquisition of
Modem-Art Ltd. None of the selling stockholders are officers or directors of
Agere.

     Except as otherwise noted above, none of the selling stockholders have had
a material relationship with Agere within the past three years other than as a
result of the ownership of the shares identified in the table above or other
securities of Agere.

                              PLAN OF DISTRIBUTION

Resales by selling stockholders



                                      10


     Agere is registering the shares on behalf of the selling stockholders. Any
or all of the selling stockholders may offer the shares from time to time,
either in increments or in a single transaction. The selling stockholders may
also decide not to sell all the shares they are allowed to sell under this
prospectus. The selling stockholders will act independently of Agere in making
decisions with respect to the timing, manner and size of each sale.

Costs and commissions

     Agere will pay all costs, expenses and fees in connection with the
registration of the shares. The selling stockholders will pay all brokerage
commissions, discounts and other expenses, if any, relating to the sale of
shares.

Types of sale transactions

     The selling stockholders will act independently of Agere in making
decisions with respect to the timing, manner and size of each sale.

     The selling stockholders may sell the shares described in this prospectus
directly to purchasers or to or through broker-dealers, which may act as agents
or principals. Such broker-dealers may receive compensation in the form of
discounts, concessions or commissions from the selling stockholders and/or the
purchasers of shares for whom such broker-dealers may act as agents or to whom
they sell as principal, or both (which compensation as to a particular
broker-dealer might be in excess of customary commissions). The selling
stockholders may also transfer, devise or gift these shares by other means not
described in this prospectus. As a result, pledgees, donees, transferees or
other successors-in-interest that receive such shares as a gift, partnership
distribution or other transfer may offer shares covered by this prospectus. In
addition, if any shares covered by this prospectus qualify for sale pursuant to
Rule 144 under the Securities Act, the selling stockholders may sell such
shares under Rule 144 rather than pursuant to this prospectus.

     The selling stockholders may sell the shares from time to time in one or
more transactions:

     o    at fixed prices that may be changed;

     o    at market prices prevailing at the time of sale;

     o    at prices related to such prevailing market prices; or

     o    at negotiated prices.

     The selling stockholders may offer the shares in one or more of the
following transactions (which may include block trades and crosses):

     o    on any national securities exchange or quotation service on which the
          Class A common stock may be listed or quoted at the time of sale,
          including the New York Stock Exchange;

     o    in the over-the-counter market;

     o    in privately negotiated transactions;

     o    through put or call options;

     o    by pledge to secure debts and other obligations;

     o    by a combination of the above methods of sale; or

     o    to cover short sales.



                                      11


     In effecting sales, brokers or dealers engaged by the selling stockholders
may arrange for other brokers or dealers to participate in the resales. The
selling stockholders may enter into hedging transactions with broker-dealers or
other financial institutions, and in connection with those transactions,
broker-dealers or other financial institutions may engage in short sales of our
Class A common stock. The selling stockholders also may sell shares short and
deliver the shares to close out such short positions; provided that the short
sale is made after the registration statement has been declared effective and a
copy of this prospectus is delivered in connection with the short sale. The
selling stockholders also may enter into option or other transactions with
broker-dealers or other financial institutions that require the delivery to the
broker-dealer or other financial institution of the shares, which the
broker-dealer or other financial institution may resell pursuant to this
prospectus. The selling stockholders also may loan or pledge the shares to a
broker, dealer or other financial institution, and upon a default, the broker,
dealer or other financial institution may effect sales of the loans or pledged
shares pursuant to this prospectus.

     The selling stockholders and any underwriters, broker-dealers or agents
that act in connection with the sale of the shares may be deemed "underwriters"
within the meaning of the Securities Act. As underwriters, any profits on the
resale of the shares sold by them while acting as principals and any
compensation to be received by an underwriter, broker-dealer or agent could be
deemed underwriting discounts or commissions under the Securities Act.

     To our knowledge, the selling stockholders have not entered into any
agreements, understandings or arrangements with any underwriters or
broker-dealers regarding the sale of the shares, nor is there an underwriter or
coordinating broker acting in connection with the proposed sale of shares by
the selling stockholders.

Indemnification

     The selling stockholders may agree to indemnify any agent, dealer or
broker-dealer that participates in transactions involving sales of shares
against certain liabilities, including liabilities arising under the Securities
Act.

Prospectus delivery requirements

     Because a selling stockholder may be deemed an underwriter, the selling
stockholder must deliver this prospectus and any supplements to this prospectus
in the manner required by the Securities Act. This might include delivery
through the facilities of the New York Stock Exchange in accordance with Rule
153 under the Securities Act.

Arrangements with broker-dealers

     Upon our being notified by the selling stockholders that any material
arrangement has been entered into with a broker-dealer for the sale of shares
through a block trade, special offering, exchange distribution or secondary
distribution or a purchase by a broker-dealer, a supplement to this prospectus
will be filed, if required, under Rule 424(b) under the Securities Act,
disclosing relevant information regarding such arrangement.

                                 LEGAL MATTERS

     The validity of the shares offered hereby has been passed upon for us by
Jean F. Rankin, Senior Vice President, General Counsel and Secretary of Agere.
As of March 3, 2005, Ms. Rankin owned 45,324 shares of Class A common stock and
2,383 shares of Class B common stock and had options to acquire 2,848,879
additional shares of Class A common stock.

                                    EXPERTS

     The financial statements incorporated in this prospectus by reference to
the Annual Report on Form 10-K for the year ended September 30, 2004 have been
so incorporated in reliance on the report of PricewaterhouseCoopers LLP, an
independent registered public accounting firm, given on the authority of said
firm as experts in auditing and accounting.



                                      12


                             AVAILABLE INFORMATION

     The prospectus constitutes a part of the registration statement on Form
S-3, which we have filed with the Securities and Exchange Commission with
respect to the Class A common stock offered hereby. This prospectus does not
contain all of the information in the registration statement. For further
information about us and our securities, see the registration statement and its
exhibits. The registration statement and the exhibits to the registration
statement, as well as the annual (containing audited financial statements),
quarterly and current reports, proxy statements and other information we file
with the Securities and Exchange Commission, may be read and copied at the
Securities and Exchange Commission's Public Reference Room at 450 Fifth Street,
N.W., Room 1024, Washington, DC 20549. You can get information about the
operation of the Public Reference Room by calling the Securities and Exchange
Commission at 1-800-SEC-0330. In addition, the Securities and Exchange
Commission maintains a Web site which provides online access to periodic
reports, proxy and information statements and other information regarding
registrants that file electronically with the Securities and Exchange
Commission at the address http://www.sec.gov.

                INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

     We "incorporate by reference" the information that we file with the
Securities and Exchange Commission, which means that we are disclosing
important information to you in those documents. The information incorporated
by reference is an important part of this prospectus, and information that we
subsequently file with the Securities and Exchange Commission will
automatically update and supercede information in this prospectus and in our
other filings with the Securities and Exchange Commission. Any statement
contained in a document incorporated or deemed to be incorporated by reference
herein shall be deemed to be modified or superseded for purposes of this
document to the extent that a statement contained herein or in any subsequently
filed document or report that also is or is deemed to be incorporated by
reference herein modifies or supersedes such statement. Any such statement so
modified or superseded shall not be deemed, except as so modified or
superseded, to constitute a part of this document. We incorporate by reference
the documents listed below, which we have already filed with the Securities and
Exchange Commission, and any future filings that we make with the Securities
and Exchange Commission under Sections 13(a), 13(c), 14 or 15(d) of the
Securities Exchange Act of 1934 (other than information furnished pursuant to
Item 2.02 or Item 7.01 of any Current Report on Form 8-K and any exhibits
relating to such items):

     (a) Our Annual Report on Form 10-K for the fiscal year ended September 30,
2004, filed with the Securities and Exchange Commission on December 13, 2004.

     (b) Our Quarterly Report on Form 10-Q for the quarter ended December 31,
2004, filed with the Securities and Exchange Commission on February 4, 2005.

     (c) Our Current Reports on Form 8-K, filed with the Securities and
Exchange Commission on October 26, 2004, January 26, 2005 and March 9, 2005 (in
each case other than any information furnished pursuant to Item 2.02 or Item
7.01 and any exhibits relating to such items).

     (d) The description of our Class A common stock contained in our
registration statement on Form 8-A, filed on March 16, 2001, including any
amendment or reports filed for the purpose of updating that description.

     You may request a copy of these filings and any exhibits specifically
incorporated by reference in these filings at no cost by writing or telephoning
us at the following address:

        Agere Systems Inc.
        P.O. Box 11082
        Church Street Station
        New York, New York  10286-1082
        (866) 243-7347



                                      13