Though unlikely, what would a merger between Microsoft and Yahoo look like? How would two companies with such different cultures combine? Would it go the way of Time Warner and AOL? Would it mire the two in years of ineffective coagulation, enabling Google to make even further strides, or would it actually help them close the gap?

Quoted: Shares of Yahoo Inc. soared as much as 19 percent to their highest level in nearly a year on Friday after two newspaper reports said the company and Microsoft Corp. were in preliminary merger talks to take on common foe Google Inc.

Quoted: But the stock pulled back after contradictory reports said the two companies may work out a joint venture or another form of cooperation that would stop short of a full merger. A source close to the situation confirmed that any talks had cooled.