Google issued a statement Feb. 3 criticizing Microsoft's bid for Yahoo, which the software vendor made public Feb 1.  

In a statement, Google's senior vice president of development and chief legal officer, David Drummond, said that "Microsoft's hostile bid for Yahoo raises troubling questions."

Drummond also suggested that Microsoft would attempt to dominate the market for Web mail and instant messaging in  the same manner as it has used its size in the past to dominate the market for PC software.

"Microsoft has frequently sought to establish proprietary monopolies—and then leverage its dominance into new, adjacent markets," Drummond said.

But rather than focusing on search and online advertising—two markets where Microsoft and Google have been competing fiercely—Drummond's letter focuses on IM and Web-based mail.

Indeed, each company has been making incursions into the other's territories in recent months. Google is developing Web-based applications that could replace Microsoft's office productivity suite of applications, while Microsoft has been looking to build social networking and community-based tools.

Forrester analyst Charlene Li blogged that a combination of Microsoft, Yahoo and Facebook could emerge as "the media company of the future."

Microsoft acquired a 5 percent stake in Facebook, a popular social networking company. 

That prospect was clearly at the root of Drummond's concerns. He noted that a combination of Microsoft and Yahoo "equals an overwhelming share of instant messaging and Web email accounts... Could a combination of the two take advantage of a PC software monopoly to unfairly limit the ability of consumers to freely access competitors' email, IM, and web-based services?"