MySpace, the world's largest social networking site, on Wednesday unveiled a long-expected joint venture with all four major music companies. In a bid to compete with Apple 's market-leading iTunes store, MySpace Music is designed to win fans with a mix of unlimited free music, comprehensive music catalogs, concert tickets, merchandising and other entertainment features.

The biggest challenge for the new venture was signing a deal with the fourth-largest music company EMI Music.

MySpace Music also signed late licensing deals with The Orchard, a large distributor of independent music from hundreds of small labels and music publisher Sony/ATV, a joint venture between Sony Corp and pop star Michael Jackson.

In April, MySpace confirmed it agreed to create a joint venture with Vivendi's Universal Music Group, Sony BMG Music Entertainment and Warner Music Group

The music industry has become frustrated with the dominance of Apple in the music business through both iTunes and popular iPod music player.

Music executives have said the refusal of iTunes to agree to variable pricing, rather than pricing every song at 99 cents or selling all albums as individual songs, has harmed sales and their bottomline.

Citing an unamed executive, Reuters reports that one that the labels would try strategies such as giving exclusive album releases first to MySpace to help support the new service in which they now all have a vested interest in helping to succeed.