Universal Music Group (UMG) is suing Bertelsmann over its relationship with Napster.

Universal is joining an existing $17 billion suit launched by major music publishers against the German-based company.

The litigants accuse Bertelsmann of encouraging illegal music downloads by investing in Napster.

Speaking to Reuters a Universal spokesman said: "Bertelsmann did not merely provide a loan to Napster; nor was it merely a passive investor in Napster. Rather, it took control of the Napster system to financially benefit itself at the expense of Universal and its artists."

Napster was lent $50 million by Bertelsmann in 2000. It never saw a return on that investment, as Napster was shut down and later went bankrupt.

Universal Music is seeking $150,000 per infringed track.

In related news, Universal and EMI last month sued San Francisco-based Hummer Winblad Venture Partners, the venture capitalists that once backed Napster.