Mithras Capital, an investment fund that, poor thing, owns 1.9 million shares of Yahoo, which amounts to a fractional percentage in the company, has suggested that Microsoft buy the joint for $22 a share, these days something like a 60% premium to its bombed-out stock price, then sell off Yahoo’s Asian and non-search interests, cut costs by $3 billion and get $2.8 billion in tax benefits.

That way Microsoft would get Yahoo’s search business for something like $10.3 billion, $2 billion less than Microsoft offered in July.

Reuters says Mithras partner Mark Nelson sent a letter outlining the proposal to Microsoft and Yahoo last Thursday.

It’s not the first time Nelson has tried to get Yahoo to sell its search to Microsoft. Back in June he wanted Microsoft to take its similar-sounding “alternative proposal” to buy Yahoo’s search business directly to Yahoo shareholders and wrote the pair a letter.

Another school of thought figures Microsoft is waiting to see if the now delayed Yahoo-Google deal survives regulatory scrutiny but Nelson thinks Microsoft has to move now “while the Yahoo-Google deal is mired in regulatory concerns and before Yahoo strikes a deal with AOL.” Nelson wants to exploit the Yahoo board’s current level of discomfit – Yahoo stock having toyed with the other time of 12 bucks last week. The board would have to drop the company’s poison pill defenses.

However, Ironfire Capital founder Eric Jackson, who sold his position in Yahoo last month when it hit $20, told the Wall Street Journal, “If I was in Redmond, I’d say why not wait a few weeks and pick this company up for a couple of bucks?’

Yahoo reports next Tuesday. The numbers could confirm rumors of sagging display advertising revenues.