Updated from 1:39 p.m. EDT

Sssssshhhhhhh.

America Online

(AOL)

has quietly linked up its two instant messaging systems. That's the word from today's

Wall Street Journal

, anyway.

According to the paper, users of ICQ, the Internet-based chat function far more popular with phreaks than with

AARP members, can use AOL Instant Messenger, another popular person-to-person chat application, to chat with other ICQers. This latest action scares the bejeezus out of competitors such as

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Yahoo!

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and

Microsoft

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, who are furiously trying to capture a portion of the instant messaging market.

But AOL spokeswoman Tricia Primrose says the move is nothing major, at least at this point. "This was an eight-month research and development test to understand some of the technical aspects of instant messaging," she said. Under the test, while ICQ users can chat with one another on AIM, they cannot chat with AIM users. And AIM users cannot chat with one another via ICQ.

Fully linking these two ways to chat would mean AOL would have 138 million users able to chat freely.

AOL finished Tuesday regular trading down 84 cents, or 1%, at $55.60.