Technology giant IBM is in talks to buy Sun Microsystems for at least $6.5 billion, Wall Street Journal said in a report.

Quoting people familiar with the matter, WSJ said that IBM was in talks to buy Sun Microsystems Inc and the deal would bolster the company's presence in the Internet, software and finance and telecommunications markets.

"The two companies have a common interest in that both make computer systems for corporate customers that are not reliant on Microsoft Corp's Windows software, and their product lines are less dependant than rivals' on Intel Corp's microprocessor technologies," the report stated.

Both companies are also strong supporters of open-source Linux and Java software, it added.

However, the daily said the people familiar with the matter have cautioned that even as the talks for the buyout are underway, a transaction might not occur.

Sun Microsystems develops innovative products and services that power the network economy.