San Francisco  - Billionaire investor Carl Icahn on Thursday officially launched a proxy fight to oust the Yahoo board in a bid to revive Microsoft's spurned deal for the internet powerhouse.

"It is quite obvious that Microsoft's bid of 33 dollars per share is a superior alternative to Yahoo's prospects on a standalone basis," wrote Icahn in a letter to Yahoo Chairman Ro Bostock. "I believe that a combination between Microsoft and Yahoo is by far the most sensible path for both companies."

Icahn nominated a strong slate of alternative board members, who will try to replace the incumbent directors at the company's annual general meeting on July 3. If successful the shareholder revolt could oust Yahoo chief executive Jerry Yang from the company he founded as a graduate student in 1994.

Icahn revealed he has bought 1.3 billion dollars of Yahoo's shares since the stock dived following the withdrawal of Microsoft's bid on May 3, and said he could seek to buy as much as 2.5 billion dollars of shares. But Icahn held out the offer of a compromise, saying that the Yahoo board could quell the mutiny be reopening negotiations with Microsoft. (dpa)