EX-99 4 jfaoct31.txt 99.3 - JOINT FILING AGREEMENT EXHIBIT 99.3 JOINT FILING AGREEMENT In accordance with Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, as amended, the undersigned hereby agree that this Statement on Schedule 13D with respect to the beneficial ownership of shares of Common Stock of Chiron Corporation is filed jointly, on behalf of each of them. This Agreement may be executed in any number of counterparts, all of which taken together shall constitute one and the same instrument. Dated: October 31, 2005 NOVARTIS BIOTECH PARTNERSHIP, INC. By: /s/ Wayne P. Merkelson -------------------------- Name: Wayne P. Merkelson Title: Vice President NOVARTIS CORPORATION By: /s/ Jeff Benjamin --------------------------- Name: Jeff Benjamin Title: Vice President NOVARTIS PHARMA AG By: /s/ Jorg Reinhardt --------------------------- Name: Jorg Reinhardt Title: Authorized Signatory By: /s/ Martin Henrich --------------------------- Name: Martin Henrich Title: Authorized Signatory NOVARTIS AG By: /s/ Frederic Krohn --------------------------- Name: Frederic Krohn Title: Authorized Signatory