$4.5 billion offer

Novartis has made a proposal to the independent directors of Chiron Corporation to acquire all of the remaining outstanding shares that it does not already own.

Novartis currently holds a 42.2% stake in the US biopharmaceutical company and has submitted a proposal to acquire the approximately 112 million fully diluted shares of Chiron for $40.00 per share in cash, or a total of $4.5 billion.

Novartis will seek to negotiate a customary merger agreement with the independent directors of Chiron's Board of Directors that would be subject to approval by a majority of the Chiron shares not owned by Novartis.

The Chiron board of directors, excluding three Novartis directors, are evaluating the offer with the assistance of Morgan Stanley and Credit Suisse First Boston.