A Yahoo investor Thursday proposed that Yahoo sell itself to Microsoft for US$22 a share, according to a report from the Reuters news service. Yahoo was trading at US$12.84 on Friday.

Mithras Capital - which owns 1.9 million shares or 0.14 percent of Yahoo - said that once the deal concludes. Microsoft could sell off Yahoo's Asian assets and non-search business to gain US$3 billion in cost savings and US$2.8 billion in tax benefits. Once the dust settles, Mithras said, Microsoft would have paid US$10 billion for Yahoo's search business -- US$2 billion less than it offered earlier this year, according to the report.

Neither Microsoft nor Yahoo could immediately be reached for comment.

Yahoo in June ended merger talks with Microsoft. At the time, Yahoo said it rejected the offer because Microsoft was only interested in its search business. The merger talks were prompted by Microsoft's US$44 billion cash and stock offer in February to buy all of Yahoo.

Mark Nelson, partner of Mithras Capital, said he planned to send a letter proposing the deal to Microsoft and Yahoo Thursday night, according to the Reuters report.

"It is imperative for Microsoft to act now, while the Yahoo-Google deal is mired in regulatory concerns, and before Yahoo strikes a deal with AOL," Nelson said in a press release. "It is imperative for the Yahoo board to embrace this proposal as the best outcome for long-suffering Yahoo shareholders.

The proposal comes just days after Yahoo and Google announced plans to delay implementing its proposed  search advertising deal that would have Yahoo running Google advertising alongside its own search results.

That partnership came under fire from major advertiser groups and prompted the US Department of Justice to hire a high-profile litigator to look into possible antitrust issues.

An antitrust think tank said the partnership could end up as a  "black hole that swallows up Yahoo," thus justifying an antitrust injunction.