The assets of the bankrupt file-sharing system Napster are up for auction for $25million.

Media firms, music retailers, record companies and venture capitalists are among the potential buyers.

The deadline for bids is August 21, with the auction set for August 27.

German publishing giant Bertelsmann is keen to buy the assets. The company is one of Napster's creditors, lending the ill-fated service more than $85million.

The $85million loan would form part of Bertelsmann's bid that it is prepared to top up by a further $9million.

But if the bankruptcy judge decides to disregard the loan, other bidders could get control of Napster for about $25m.

In its hey-day Napster was a popular file-swapping site among music fans.

The service became a target for legal action from record companies and musicians who accused it of music piracy.