Microsoft chief executive Mr Steve Ballmer failed to clinch a deal yesterday with Mr Mario Monti, the EU's Competition Commissioner, over the Brussels watchdog's long-running antitrust case against the software giant.

Both sides said discussions were continuing after the four-hour meeting but it was unclear whether the two main protagonists would meet in person again. Mr Ballmer was expected to stay in Brussels last night.

The Microsoft chief had decided to come to the Commission's headquarters amid hopes within Microsoft that earlier talks had paved the way for a settlement. But in their meeting, the two men were unable to agree on how far-reaching a compromise deal should be.

Microsoft has worked on specific proposals dealing with the Commission's concerns about competition in the markets for computer servers and media player programs. But it has been unwilling to agree that a deal should also bear on other, separate areas with which the Commission might also be concerned.

The Commission is scheduled to rule on March 24th that Microsoft has unfairly used its virtual monopoly over personal computer operating systems to elbow out rivals in the markets for computer server systems and media player software.