Ivory Investment Management LP, a Los Angeles-based hedge fund and one of Yahoo Inc.’s largest shareholders, called Wednesday for the Internet company to pursue a sale of its search engine unit to Microsoft.

In a letter to Yahoo’s board, Ivory Managing Partner Curtis Macnguyen said a deal for the search unit could generate $15 billion upfront, which would give shareholders a return of $24 to $29 per share, or roughly double the company’s Wednesday afternoon share price of $12.97.

Under the proposed deal, Microsoft would own Yahoo’s search unit, but Yahoo could retain as much as 80 percent of the revenue generated by search activity.

“We have regrettably watched the company not only mis-execute operationally, but also mishandle, in our opinion, a bona fide offer from Microsoft to acquire the entire company for $31 per share, which now represents an over 150 percent premium to the current stock price,” Macnguyen said in the letter.

Ivory, which has $3.5 billion under management, owns 21.4 million, or about 1.5 percent, of Yahoo’s outstanding shares.

Shareholder unrest over Yahoo’s rejection of a $47.5 billion offer from Microsoft recently led Yahoo Chief Executive Jerry Yang to announce his resignation.