Larry Ellison has used his keynote address at Oracle OpenWorld 2009 to start a war of words with IBM over server performance.

Oracle's chief executive said that he is fighting back against what he alleged were "lies" from IBM about the future of Solaris and Sun Microsystems, and the platforms and their performance.

Ellison said that he was so confident in his platforms that he would give $10m (£6.3m) to the company that showed its database running at less than double the speed of the same application running on IBM.

"IBM started to go to customers and say: 'You know, Oracle's going to get out of the hardware business. It's going to sell off Sun hardware. As a Sun company can you deal with this kind of uncertainty?'" he said.

"If IBM wants to compete we will compete. We are not selling the hardware business, no part of the software business are we selling."

Ellison claimed that investment in the hardware would make it faster and more efficient, backing up Sun chairman Scott McNealy's promise that investment in Sun technologies would rise in the future.

When Oracle first made a move on Sun, Ellison said that the company had taken out advertisements to reassure customers that their Sun systems were safe. Oracle put out a misleading advert about this and was fined, but is now putting out a new advert offering $10m.

"We are going to challenge any enterprise company to take one of its existing database applications, that it has not run, and if we cannot run that database application at least twice as fast on Sun gear we'll give it $10m. Oh, and IBM, you're welcome to enter."

Ellison also reaffirmed Oracle's commitment to the server business. "We hope this [removes] some of the uncertainty. We're in it to win it," he said.

"We are looking forward to competing with IBM in the systems business, and we think the combination of Sun and Oracle is well equipped to compete successfully against the giant."