Under the deal, the three companies would form a new entity through which they would jointly own the Web portal, the person, who requested anonymity because release of the information was not authorised, said on Wednesday.
AOL has been successful of late at generating online content, but America Online's business prospects have suffered as more people switch from dial-up Internet access to high-speed connections.
If the deal is finalised, one possibility would be for the AOL portal to replace the broadband Internet Web sites of New York-based Time Warner and Comcast. The three companies plan to leverage their content and consumer reach to create a Web portal powerhouse, the person said.
Google is the nation's most popular search engine, while Comcast and Time Warner are the top two cable operators.
The preliminary discussions follow reports that one of Google's biggest rivals, Microsoft Corp, and Time Warner have been discussing for several months a possible alliance that would unite AOL with MSN, another major portal.
A deal between AOL and MSN would loom as a financial threat to Google because AOL is the biggest player in its online advertising network.
AOL accounted for 11 percent of Google's $2.6 billion in revenue during the first half of this year.