launched in May last year with just 30 tracks to download, but quickly became popular and expanded its library of music. It offers the ability to play music on demand, free downloads with ads, and a charge for downloads without ads.
Warner music is the second major music label to offer downloads through the We7 website after Sony BMG signed up with the service in March.
We7 is currently in talks with other record labels including EMI and Universal and plans to grow the current library of 1m tracks to 3m by the end of the year.
Steve Purdham, founder investor and CEO of We7, said: "A download site is only as good as the music which is on there. We want to grow our collection so that our customers don't have to look elsewhere for their favourite tracks.
"We are very excited to be partnering with Warner as our customers will now be able to download its artists' back catalogues, as well as new songs."
Music from the We7 website can be downloaded on to any type of MP3 player, including Ipods.
Warners artists available for on-demand listening and download include James Blunt, My Chemical Romance and Muse.