Sirius XM Radio has boosted its subscriber and financial outlook for 2010, following a recent set of better-than-expected first-quarter results.

The satellite radio company now expects net subscriber additions of approximately 750,000, up from "more than 500,000" previously.

Sirius also now eyes pro forma adjusted profit from operations to be approximately $575 million. Previously it had forecast $550 million.

Plus, it slightly adjusted its pro forma revenue guidance to approximately $2.75 billion from "over $2.70 billion."

"Our continuing strong operating performance, the recovering economy and improving auto sales support our increase in guidance today," said CEO Mel Karmazin.

Sirius XM had not immediately raised its outlook after reporting its first-quarter results on May 4, saying it preferred to remain cautious in its guidance. Some analysts had hoped for the higher full-year expectations.

Sirius shares closed up 1.9% at $1.09.