Microsoft expects to win an appeal against a US court ruling which could force the break-up of the company, its chief executive Mr Steve Ballmer said yesterday.

Speaking during a visit to Vienna, Mr Ballmer also said he expected the company to complete its purchase of a stake in British cable services provider Telewest Communications from MediaOne Group "within months".

District Judge Thomas Penfield Jackson ruled in April that Microsoft, the world's largest software producer, broke US antitrust law by abusing its dominant position in personal computer operating systems.

The US government, which was behind the accusations, wants the company to be split in two. On Monday it accepted only minor changes offered by Microsoft to its divestiture plan, which is supposed to prevent future antitrust violations.

Judge Jackson is expected to rule in the state's favour, later this week after receiving the company's reply brief today ,but Mr Ballmer said Microsoft expected the ruling to be set aside pending appeal to higher courts.

"We remain convinced of the propriety of our legal position despite the negative ruling we will receive from the judge this week," Mr Ballmer said. "We fully expect to prevail on the most important points on appeal, which is that we remain an integrated company and that we retain our right to continue to respond to customers and integrate new capabilities into Windows."

Mr Ballmer rejected suggestions that the break-up of the giant could be positive for software users and the company itself.

"I know that our company will be much less able to help customers and consumers with the next generation of things they want to do if we don't exist as an integrated company," he said.

"My opinion is that the break up would be very bad for our shareholders and it would be even worse, much worse for our consumers."