News that Microsoft has been fined for violating MP3 patents belonging to Alcatel-Lucent could have widespread fallout for the industry.

Experts now suggest the US ruling could lead to hundreds of firms - including Apple and RealNetworks - being pursued for payments relating to the format.

"Any of the companies that have licensed and implemented that technology have to have great concern about this verdict," said Microsoft vice president Thomas W Burt.

At the heart of the case is the question whether Alcatel-Lucent should be paid for technology developed by experts at Germany's Fraunhofer Institute and Bell Laboratories - which Alcatel now owns.

Microsoft says it should not have to pay fees to Alcatel as it paid $16m to license the MP3 technology from the Fraunhofer Institute.

But Alcatel claims that as it now owns Bell, and has done since 2003, Microsoft should have been paying it for its share of the patent.

And it seems the Federal District Court in San Diego agrees - it ordered Microsoft to pay Alcatel $1.52bn, an award both companies say is the largest patent award in history.

The technology industry is watching the case closely as it could mean that Alcatel will soon be knocking on the door of hundreds of firms demanding payment for their use of the MP3 format.