Washington, D.C.-based XM Satellite Radio [XMSR] today raised its subscriber guidance for year-end 2004 from 2.8 million subscribers to 3.1 million. The move came in conjunction with the company’s release of favorable financial results for second-quarter 2004.

XM’s $53 million in second-quarter revenues was in line with Bear Stearns’ estimate. Analyst Bob Peck wrote in a research note this morning that he was particularly impressed with subscriber acquisition costs of just $57 per sub, $10 cheaper than his $67 estimate.