Microsoft has reached a settlement with Montana consumers who filed a lawsuit alleging that the company violated the state's antitrust and unfair competition laws.

The settlement has received preliminary approval from the Montana First District Court.

Under the terms of the agreement, up to $12.3m (£7.6m) will be given as vouchers that can be used to buy desktop, laptop and tablet computers by any manufacturer, any software used with those computer products, and specified peripheral devices for use with computers.

Microsoft will donate half of any unclaimed settlement proceeds, also in vouchers, to Montana's most needy public schools. The vouchers can be used to purchase hardware products, Microsoft and non-Microsoft software, and professional development services.

The company said that 325 schools, serving more than 38,325 students, will be eligible to receive assistance. This represents nearly one quarter of all Montana students.

"This settlement benefits Montana consumers, businesses and schools. We are proud to have achieved this result," said Mike Meloy, attorney for the plaintiffs.

Brad Smith, general counsel for Microsoft, said: "We're pleased by the opportunity to help schools all across Montana get the computers and software they need.

"This settlement allows us to focus on the future and building great software, and avoids the cost and uncertainty of litigation."