The National Music Publishers" Association is suing XM Satellite Radio, saying that XM violates copyright laws with a service called "XM (plus) MP3". It enables users to store and replay songs on certain devices, something the group claims isn"t covered by the royalties the company pays to music publishers for broadcast rights. Like traditional radio broadcasters, satellite radio services must pay the publishers of music and record labels royalties for the right to broadcast music. The songs remain on the device as long as the customer subscribes to XM. XM spokesman Chance Patterson said the lawsuit by the NMPA was without merit and it "simply represents a negotiating tactic to gain advantage in our ongoing business discussions." The music publishers" lawsuit is similar to another filed against XM last year by the Recording Industry Association of America. That case is still pending.