independent directors announced Monday that they have rejected an offer from
to acquire the approximately 58% of Chiron shares Novartis does not already own for $40 per Chiron share in cash.
"Over the 10 years since Novartis has been Chiron's largest stockholder, Chiron has regularly discussed with Novartis a number of strategic initiatives, including mergers, significant acquisitions and other transactions, including transactions initiated by Novartis," the Chiron directors said in a statement.
"After thorough analysis and consideration of Novartis' offer to acquire the shares of Chiron it does not already own for $40 per share in cash, the independent directors of Chiron have determined that this offer is inadequate."
Novartis holds a 42.2% stake in Chiron and had submitted a proposal last week to acquire the rest of the Emeryville, Calif., biopharmaceutical company.
Chiron shares shot up 18% to $43.15 after the $4.5 billion offer was revealed. The stock hadn't reached the $40 level since Chiron's announcement last fall that it couldn't provide the Fluvirin vaccine to the U.S. because of problems at its manufacturing plant in Liverpool, England.
looked at Novartis' move last week.