Virgin Records sued the band and front man Jared Leto in Los Angeles on Friday, claiming they refused to deliver three albums as required by its contract.
The band's last album, "A Beautiful Lie," was released in 2005.
A publicist for Leto, an actor who starred in the film "Requiem for a Dream" and the TV show "My So-Called Life," did not return a message Friday.
According to the lawsuit, the band "repudiated" a 1999 contract in July.
Despite the absence of a new album, the band's hit "From Yesterday" was deemed one of 2007's Top 10 "Hot Modern Rock Songs" by Billboard magazine.