Microsoft's bankers approached Facebook about a takeover of the social networking site, the Wall Street Journal reported.
The company sent out signals to Facebook, to see if it would be open to a full buyout. There aren't active discussions but Microsoft has expressed interest over the past three years, according to the Journal.
Microsoft has recently abandoned its efforts to acquire Internet portal Yahoo to better compete with Google Inc for advertising dollars online.
Microsoft chief executive Steve Ballmer, in discussing Microsoft's bid for Yahoo, has said that Microsoft needs a much larger base of users to effectively compete with Google for ads.
He has previously named Facebook as one of a few Internet properties with significant size. Others he mentioned include MySpace, MSN, Yahoo, Google, Baidu and AOL.