Sirius Satellite Radio announced Tuesday that it has signed up more than 800,000 subscribers and expects to reach the 1 million mark by the end of the year, narrowing the gap with rival XM Satellite Radio. "Sirius is on a roll," former Viacom executive and new Sirius CEO Mel Karmazin said in a statement. Sirius riled the nascent satellite radio industry last month by
Sirius and XM both emerged on the market about three years ago with similar technologies and business plans, charging monthly fees to let subscribers access dozens of channels of original audio programming beamed directly by satellite to special receivers in cars and home stereo systems. XM reported last month that it had 2.5 million subscribers. Analysts estimate that XM needs 4.5 million subscribers and Sirius 3.4 million to break even.