MySpace announced its long-awaited joint music venture this morning, unveiling details about a far-ranging service it will offer in partnership with three of the four major record labels.

The revamped MySpace Music will offer ad-supported streaming music and videos, paid MP3 downloads with no digital rights management (DRM) usage protections and other content and services . The venture vaults MySpace into competition with Apple for hegemony in the digital music arena.

"We're really excited to partner with these industry leaders to create not only the most innovate and dynamic group in the marketplace but on the planet," said MySpace co-founder and CEO Chris DeWolfe on a conference call announcing the initiative. "A venture like this had never been done before, and it is truly history in the making."

DeWolfe described the venture as a "360-degree platform" that would create a "new way of consuming and experiencing music online that everyone can participate in." In the modern world of music, he said, artists need to loosen control of their music and adapt to new ways of interacting and engaging with consumers.

The three main components of MySpace Music will be the home page, the artists' profile pages and the ad-supported services and the content for sale, such as downloads and ringtones.

MySpace is still negotiating details with EMI, but Sony BMG, Warner Music and Universal Music Group are onboard. Universal's long-standing copyright-infringement suit against MySpace had been holding up the deal, but the two groups are believed to have settled.

DeWolfe declined to answer questions about how much the downloads will cost (he said pricing would be "competitive"), whether the licensing agreements are exclusive or a timetable for when the service would be rolled out to MySpace users outside of the United States.

The move comes as the major record labels are scrambling to break Apple's grip on digital music. Last month, the NPD Group reported that Apple's iTunes service jumped ahead of Best Buy to become the second biggest music retailer in the country.

A leaked copy of NPD's latest research indicates that iTunes has now moved ahead of Wal-Mart, selling more music -- digital or disc -- than any other retailer in the country.

Each of the big four record labels has licensed its catalog to Amazon's online music store with no DRM protections in the hopes of making a dent in Apple's market position. Only EMI has struck a similar agreement with Apple.

For MySpace, the move reinforces the importance of music to its brand. MySpace has long given struggling bands a forum for promoting and sharing their music, and it is a near impossibility to find an established band without a MySpace page. DeWolfe said that more than 5 million bands have profile pages on MySpace Music, and the site has more than 30 million unique monthly visitors.

In December, MySpace launched Transmissions, featuring original music videos and paid downloads from established artists.

MySpace Music will launch as a separate entity, presumably with an equity investment from the partner labels, though DeWolfe declined to discuss the financial arrangements. Amit Kapur, MySpace's chief operating officer, said that MySpace was searching for a management team for the new site.