The site, which hosts the subscription-based Rhapsody service, already has deals with the four other "major" labels and is thought to be the first service with access to artists from all the "big five" record companies.
Listen.com is up against Pressplay, the download service run by Universal, Sony and EMI, and MusicNet, backed by Warner, EMI and Bertelsmann.
The Rhapsody service offers access to all of San Francisco-based Listen's licensed music for $9.95 (£6.53) and allows the user to stream songs from a desktop computer.
Universal's vast roster of artists includes Eminem, whose recent new album had its release date changed twice in an effort to beat internet "pirates" and illegal song-swapping harming sales.
Rhapsody only supports CD burning - copying songs to CD - for its classical selection, and users cannot download music to portable mp3 players, but it does offer a large collection of music.
Competing services
There are concerns that take-up for subscription services is low, as users prefer to hunt around for illegal services.
Listen.com chief executive Sean Ryan admitted only small numbers of people have signed up for any of the competing services so far.
MusicNet and Pressplay have yet to reveal how many users they have picked up so far.
But Mr Ryan added: "Three years ago, the labels really hoped the internet would go away because they couldn't see any benefit to it.
"In the last year, they've grown to understand the internet is not going away and the internet can grow their businesses."
~RS~a~RS~International~RS~q~RS~~RS~z~RS~50~RS~)