Microsoft offered $40 a share to buy Yahoo in 2007 — $9 more than their February 2008 offer — according to court documents unsealed in a class action lawsuit to protest the failed buyout.

The world's largest software maker privately made "a January 2007 acquisition proposal offering about $40 per share" to Yahoo management, at the time headed by chief executive Terry Semel, according to a document unsealed by a Delaware court on Monday.

The plaintiffs, the Police & Fire Retirement System of the City of Detroit and the General Retirement System of the City of Detroit, filed the complaint after Yahoo rejected Microsoft's buyout offer of $31 a share in February.

Microsoft's offer marked a "high" 62 percent premium over Yahoo's then-current market price and "reflected Microsoft's express desire to complete a negotiated acquisition," said the document, posted on the website of Bernstein Litowitz Berger & Grossmann, the lawyers for the plaintiffs.

Yahoo chief executive Jerry Yang rejected the $31-per-share offer in February, angering some shareholders.

Microsoft says it broke off takeover talks in late April after it upped its 1 February bid of $44.6-billion by $3-billion and Yahoo's board still wanted more.

Yahoo shares were trading at around $26 on Tuesday.

"Due to their personal interests in maintaining Yahoo's independence and their strong antipathy to Microsoft, (Yahoo co-founders Jerry Yang and David Filo) failed to consider and respond in good faith to the acquisition offers by Microsoft to the detriment of Yahoo and its shareholders," the document said.

AFP