A judge in Iowa's Polk Country District Court Wednesday granted preliminary approval to a settlement in one of the last class-action lawsuits faced by Microsoft in the wake of the antitrust case brought against it by the US government in the 1990s.

The agreement dismisses antitrust and damage claims that had been raised in the Iowa case, which could have amounted to $1 billion or more, according to Microsoft.

"This case concerned issues that have long since been resolved, and we're very pleased to put this chapter behind us and to focus on the future," said Rich Wallis, associate general counsel for Microsoft, in a statement.

Microsoft and the complainants announced the Comes v. Microsoft class action lawsuit settlement in February, but Judge Scott Rosenberg's preliminary ruling allows the parties to reveal details of their agreement.

The agreement, among other things, calls for Microsoft to pay up to $179.95 million to individual users and businesses that bought Microsoft software between 18 May 1994 and 30 June, 2006.

People in Iowa who purchased the products will be able to receive $16 for OSes; $29 for Office, $25 for Excel, and $10 for Word. Individual users will get cash. Volume buyers will get vouchers for products from Microsoft, its competitors and others.

Microsoft faced a wave of class-action lawsuits in the wake of US District Court Judge Thomas Penfield Jackson's finding, in November 1999, that Microsoft has monopoly power in the desktop operating system market. That finding was made in the government's antitrust case against the software maker.

Since then, Microsoft reached a remedy agreement with the government, which continues to be monitored by the US District Court for the District of Columbia.

A final approval hearing for the Iowa case is scheduled for 31 August. Meanwhile there is one other case still scheduled to go to trial, in Mississippi.