Google

(GOOG) - Get Report

and

Comcast

(CMCSA) - Get Report

are in "serious discussions" about buying a minority stake in

Time Warner's

(TWX)

America Online,

The Wall Street Journal

reported.

Citing people familiar with the situation, the paper said the talks focus on AOL's Web portal, not its fast-eroding dial-up Internet access business. The deal would value AOL around $20 billion, the report said, noting that any bid would be worth considerably less because the dial-up operation is responsible for the vast majority of AOL's cash generation.

The news comes as the Internet business undergoes a huge metamorphosis. AOL, whose parent is under pressure from restive shareholder Carl Icahn, has previously been reported talking to

Microsoft

(MSFT) - Get Report

over a possible combination of AOL with the MSN online service.

On Wednesday, Microsoft and

Yahoo!

(YHOO)

agreed to allow interconnection of their also-ran instant messaging systems. And last month

eBay

(EBAY) - Get Report

branched into voice over Internet protocol phone service with its $2.6 billion agreement to buy Skype.