Responding to the FCC petition, XM/Sirius said in a joint statement: "The NAB opposes the merger of XM and SIRIUS to protect AM/FM radio from competition, not to protect consumers.

"As more and more consumers voice their support for the merger, the more fearful of increased competition the NAB becomes and the more desperate their actions in response.

"The NAB's allegations are unfounded and their recent filing is just an attempt to stall the process. We look forward to continuing to work with the FCC and are confident they will weigh the transaction on its merits, recognize that it is in the public interest and approve the merger by the end of the year."