UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 -------------------------------------------------------- FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 25, 2005 Chiron Corporation -------------------------------------------------------------------------------- (Exact name of registrant as specified in its charter) Delaware 0-12798 94-2754624 -------------------------------------------------------------------------------- (State or other (Commission (IRS Employer jurisdiction of File Number) Identification No.) incorporation) 4560 Horton Street, Emeryville, CA 94608 -------------------------------------------------------------------------------- (Address of principal executive offices) (Zip Code) Registrant's telephone number, including area code (510) 655-8730 -------------- N/A -------------------------------------------------------------------------------- (Former name or former address, if changed since last report) -------------------------------------------------------- Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): [ ] Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) [ ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) [ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) [ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Item 2.02. Results of Operations and Financial Condition. On October 25, 2005, Chiron Corporation (the "Company") issued a press release announcing earnings for the quarter ended September 30, 2005. A copy of the Company's earnings press release is attached as Exhibit 99.1 to this report. The information in this Current Report on Form 8-K, including the exhibit attached hereto, is furnished pursuant to Item 2.02 and shall not be deemed to be "filed" for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section. Item 9.01 Financial Statements and Exhibits (a) Financial statements of businesses acquired. -------------------------------------------- Not applicable. (b) Pro forma financial information. -------------------------------- Not applicable. (c) Shell Company transactions. --------------------------- Not applicable. (d) Exhibits. --------- Exhibit Number -------------- 99.1 Earnings press release issued October 25, 2005. # # # 2 SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. CHIRON CORPORATION ------------------ (Registrant) Date: October 25, 2005 By: /s/ Ursula B. Bartels --------------------- Ursula B. Bartels Vice President, Secretary and General Counsel 3