XM Satellite Radio and DirecTV, Inc. have signed a joint marketing agreement designed to drive XM subscriber growth by giving DirecTV satellite television customers value-added offers for XM. Specific elements of the proposed marketing program were not disclosed.

“DirecTV customers already understand the advantages that come with satellite entertainment — programming variety, superior reception and great value,” said Hugh Panero, XM’s president and CEO and Roxanne Austin, DirecTV president and COO, in a joint statement.

“XM looks forward to providing DirecTV customers with a premier nationwide radio service for the car and home that revolutionizes radio the same way DirecTV revolutionized television.”

XM is transforming radio, an industry that has seen little technological change since FM, almost 40 years ago. XM’s programming lineup features 100 coast-to-coast digital channels: 71 music channels, more than 30 of them commercial-free, from hip hop to opera, classical to country, bluegrass to blues; and 29 channels of sports, talk, children’s and entertainment.

XM radios are available at major electronics retailers nationwide including Best Buy, Circuit City, Tweeter, Ultimate Electronics, participating RadioShack Dealers and Franchisees, Crutchfield, Good Guys, CarToys, Audio Express and Sound Advice; and at independent retailers.