SpiralFrog, a new music download service, on Tuesday said it would make Vivendi's Universal Music Group's catalog available for free legal downloading in the United States and Canada.

The new advertising-supported service, due to launch later this year, joins the ranks of rivals battling for a piece of the digital music market in the shadow of Apple Computer Inc's (AAPL) dominant iTunes music store.

New York-based SpiralFrog said it would offer users of its free, Web-based service the ability to legally download music of Universal's roster, which includes U2, Gwen Stefani and The Roots.

"Offering young consumers an easy-to-use alternative to pirated music sites will be compelling," SpiralFrog Chief Executive Robin Kent said in a statement.

Kent said SpiralFrog's business model is based on sharing income from advertising with content partners like Universal.

The company's research revealed that consumers are willing to "pay" for their content by watching non-intrusive, contextually-relevant, targeted advertising, Kent said.

According to SpiralFrog's web site, Kent is a former chairman and CEO of media communications agency Universal McCann Worldwide.

SpiralFrog said its target audience is people between the ages of 13 and 34.