IBM is in talks to buy Sun, the Wall Street Journal reported today.

IBM may pay as much as $6.5 billion in cash for Sun, the newspaper reported on its Web site, without naming its sources. That amount of money would be nearly double Sun's closing share price on Tuesday of $4.97 per share.

The report cautioned that while the two companies are holding discussions, a transaction may not occur. If it does, it will dramatically expand IBM'sserver market share,