Internet radio station / social network / E-consultancy’s favourite web app Last.fm has concluded a content deal with Sony BMG, which the company’s extensive back catalogue available to Last.fm listeners.

This deal will give Last.fm, which now has around 20m worldwide listeners, the largest music catalogue of any online radio service.

Last.fm co founder Martin Stiksel welcomed the deal:

“This partnership affords Last.fm users a whole new set of terrific content for building community. We’ve always aimed to have everything ever recorded available to listen to on our site, and having access to Sony’s collection of some of the world’s most popular music takes us another huge step closer.”

The Sony deal follows similar partnerships that Last.fm has arranged with Warner Music, EMI, as various indie label groups, including The Orchard and IODA.

Last.fm was recently snapped up by CBS for $280m in the largest ever UK Web 2.0 acquisition.