Sirius XM Radio (NASDAQ: SIRI) has announced that it ended the year with nearly 21.9 million subscribers, reporting approximately 540,000 net new subscribers in the fourth quarter and approximately 1,700,000 for the full year 2011.

"Based on preliminary subscriber data, we are very pleased to announce that SiriusXM exceeded its subscriber guidance for the year. Our subscriber growth accelerated in 2011 as net additions grew approximately 20%, delivering our best year for net additions since the merger and demonstrating the strong continuing demand for our unmatched audio content," said Mel Karmazin, Chief Executive Officer, SiriusXM.

The company reiterated its existing financial guidance for 2011 and 2012 and expects to announce 2012 subscriber guidance and complete 2011 results in February.