Yahoo CEO facing possible rebellion after spurning Microsoft

Even some of Yahoo's own employees may be irritated because virtually all of them own stock options.

What's more, Microsoft had planned to offer $1.5 billion in retention packages to the thousands of Yahoo employees it wanted to stay on after a takeover.

To help boost its short-term profits and its stock price, Yahoo is widely expected to form a long-term advertising partnership with Google.

Although the final details are still being ironed out, Yahoo wants to hire Google to place some of the text-based ads that appear alongside the search results on its Web site. It's a task that Google already handles for scores of Web sites, including AOL and Ask.com.

Both Yahoo and Google have said they were encouraged with the results of a two-week trial run completed last month.

But turning to Google for help would be a humbling step for Yahoo after spending more than $2 billion to acquire and build its own technology.

An alliance between Google and Yahoo also would face antitrust hurdles because the two companies combined control more than 80 percent of the U.S. search advertising market.

Although Google's superior technology would help boost Yahoo's profits in the short term, some analysts worry it could be a mistake for Yahoo to surrender any control over such a lucrative piece of the online ad market.

Yahoo also has been exploring a possible merger with AOL's Internet operations but may now have to contend with a competing offer from Microsoft.

Yahoo also might attempt to placate shareholders by buying back stock.