A US Federal judge has approved the $1.53bn damages awarded to Alcatel-Lucent for Microsoft's patent infringements with its Windows Media Player. 

The award was originally made back in February by a jury, but had to be signed off by a Federal judge.  

San Diego US District Court Judge Rudi M Brewster agreed with the original verdict that Microsoft's Windows Media Player software infringes on two patents owned by Alcatel-Lucent.

Microsoft had argued that it had licensed the technology from German research group Fraunhofer Gesselschaft, which it claims is the actual owner of the technology. 

The software giant said that it will challenge the ruling at a hearing in June, following a patent win against AT&T in the US Supreme Court earlier this week.  

AT&T had claimed that Windows infringed on its digital speech technology, but the court ruled that US patent law does not apply to software sent to foreign countries. 

The same ruling rejected a claim that AT&T was entitled to damages for every computer manufactured outside the US that uses the speech technology.

Another lawsuit brought by Alcatel-Lucent over two patents for computer interface technology is due to go to trial in three weeks' time with Microsoft, Dell and Gateway as defendants.