The judge who ordered the break-up of Microsoft said he would consider resigning from the case if it was returned to his court for additional hearings.

In June, Judge Thomas Penfield Jackson ruled that Microsoft be split into two: an applications company and an operating systems vendor. But the case, which is now with the Appeal Court, could once again land on his lap if the appellate judges decide to send it back for additional arguments.

Speaking at a US law school seminar on Friday, he told attendees that he would consider stepping aside from the case if the Appeals Court judges do not back his ruling and throw the case back.

Judge Jackson also hinted that he was not happy with the break-up decision. He said the plan "was never my remedy of choice and is not even today". Before the landmark ruling was made, he said a two-way split would create two separate monopolies, and instead raised the possibility of three organisations, with the addition of an Internet Explorer company.

But yesterday he said he was left with no choice but to follow the wishes of the plaintiffs when attempts to get Microsoft to settle failed. In its appeal Microsoft is arguing that Judge Jackson allowed only a one day hearing on the break-up and that this did not give it enough time to present evidence against the plaintiffs.

The Appeals Court will begin hearing Microsoft's appeal in late February.