Sun is willing to revive acquisition talks with IBM if the latter company "makes a stronger commitment to complete the purchase," according to Bloomberg News.
Sun declined to comment on the report, which cited two unnamed sources familiar with the matter. IBM did not immediately respond to a request for comment.
Meanwhile, a separate report from CNBC, also citing anonymous sources, said Sun approached IBM a couple of days ago about reopening talks.
But IBM has cooled considerably on the prospect of acquiring Sun, due to the potential for a long and intense review by government regulators concerned about anti-trust issues, the report added.
IBM "may not be interested in buying Sun at any price," according to one source cited in the CNBC report. Big Blue has not formally told Sun it has ruled out such a deal, a source also told the network.
IBM shares were up roughly US$2.78 on the news during afternoon trading, while Sun's were up about $0.25
Sun's board of directors declined an offer IBM made on 4 April. because the price was too low, according to The New York Times. Sun also believed the proposed deal gave IBM too much leeway to walk away, according to a Wall Street Journal report.
While neither Sun nor IBM has officially confirmed the existence of merger talks, the companies have reportedly been in discussions since mid-March or earlier, with the drama playing out in a series of leaks to the media.
The possible merger has been valued at about US$7 billion. However, CNBC's report said Sun is now "willing to be far more flexible on price and terms."
If it proceeds, the deal would boost IBM's lead over Hewlett-Packard in the server market. IBM took 31.4 percent of worldwide server revenue in 2008, followed by HP with 29.5 percent, Dell with 11.6 percent and Sun with 10.1 percent, according to figures from IDC.