Microsoft will file its antitrust case appeal with the US Appeals Court by October 2, a company spokesman has confirmed.

This follows the US Supreme Court’s decision not to hear Microsoft's antitrust appeal directly.

The Department of Justice (DOJ), which, along with 19 US states, brought the antitrust case against Microsoft, will reply with its own proposed brief schedule by October 5 – with a further round of reply briefs due on October 10, Microsoft revealed.

The DOJ and the US states sued Microsoft, arguing that the company has engaged in illegal business practices, aimed at squashing competition, and used its desktop operating systems monopoly to make inroads into other markets.

The judge hearing the case, Judge Thomas Penfield Jackson, ruled in favour of the government’s case in June, ordering that Microsoft be broken up into two companies - an operating-systems business and an applications company. He also imposed a number of behavioural restrictions on the software giant.

In June, Judge Jackson sent Microsoft's appeal to the Supreme Court. His ruling against the software vendor is on hold pending a decision on Microsoft's appeal.