Google and Comcast are talking about investing in Time Warner's America Online division, a move that could shift the geopolitics in the Internet world by creating new alliances between online search and entertainment giants. Google, which already powers the Dulles-based AOL's Internet search tool in the United States and Europe, wants to strengthen and expand that relationship -- as well as derail AOL's talks about a similar deal with Microsoft.

America Online is trying to find ways to keep customers coming back to its Internet community while parent company Time Warner seeks ways to expand its Internet empire.

Through these competing negotiations, AOL has become a powerful player in the global battle between Internet titans Google and Microsoft, which are vying for the attention of millions of Internet users. AOL could augment both companies' empires by adding users of AOL.com, AOL dial-up Internet service and AOL's affiliated Web sites.

A Microsoft-AOL alliance poses a threat to Google because AOL uses Google's search engine and is its largest source of revenue. On the other hand, an alliance between Google, AOL and Comcast would make a formidable enemy for Microsoft.

First, Microsoft proposed replacing Google with its MSN Search on AOL's Web sites. At the same time, Microsoft offered to combine its own MSN Internet service and pour cash into AOL. Those talks are continuing, though insiders said such a deal appears less likely.

The proposed MSN-AOL alliance prompted Google to enter the fray and propose an alternate deal with AOL. Meanwhile, Comcast's primary interest is in marketing its own high-speed Internet service to AOL's large but shrinking base of dial-up Internet users.

Microsoft yesterday made a retaliatory move. Microsoft and Yahoo joined forces to allow millions of their instant message users to chat wit