UPDATE 2-SiriusXM raises full-year subscriber forecast

* Will add 446,000 new subscribers for Q3

* Raised full-year forecast to 1.8 mln net additions

* Considering shareholder return

(Adds more executive comment, background)

By Jennifer Saba and Peter Lauria

Oct 10 (Reuters) - Sirius XM Radio Inc CEO MelKarmazin said the company will add 446,000 new subscribers forthe third quarter and raised its full-year forecast to 1.8million net additions.

Karmazin gave the updated business outlook for the satelliteradio broadcaster while speaking at Liberty Media Corp's

annual investor day on Wednesday. Liberty, controlledby billionaire John Malone, is Sirius's largest shareholder witha stake of just under 50 percent.

Liberty has been trying for months to wrest full control ofSirius, going so far as to file a petition with the U.S. FederalCommunications Commission to replace the company's board.Liberty has argued that Sirius should be more aggressive aboutpursuing better technology and expanding internationally.

Karmazin gave no indication during his presentation aboutwhether he will leave Sirius or renew his contract, which is dueto expire at the end of the year. Analysts didn't put thequestion to Malone after the executive presentations.

Karmazin, who famously clashed with Sumner Redstone while atViacom Inc , is known for his disdain of working for acontrolling shareholder, and has indicated that Liberty likelywouldn't need him stick around if it took control.

Liberty acquired an initial stake of about 40 percent inSirius in 2009 as part of a deal in which it loaned thesatellite radio provider $530 million to help stave offbankruptcy.

Under Karmazin, Sirius has grown its subscriber count to23.4 million as of the end of the third quarter, and maintainsan estimated 70 percent market share of new cars sold in theUnited States. Karmazin also helped negotiate new contracts tokeep signature talent on the air, most notably popular "shockjock" Howard Stern.

Still, Sirius is on the hunt for potential acquisitions.Karmazin said that the company looked at four potential buysthis week.

"There is nothing out there we have seen that is appropriatefor the company to do," he said.

In place of an acquisition, Karmazin said that its pile ofcash would be better served in the hands of shareholders butthat decision is ultimately up to the board.

A raft of competitors including Clear Channel Communicationsand the mostly free online streaming music company Pandora Media, which has legions of listeners and has been steadilygaining market share, hasn't stopped Sirius.

Indeed, Karmazin said that one of Sirius' major advantagesover terrestrial radio was that it was able to put on "adultcontent."

"We don't just have to put on programming appealing tochildren," Karmazin said.

Sirius raised its net subscriber forecast for this year to1.8 million from 1.6 million. The company expects to end theyear with roughly $3.3 billion in revenue and about $700 millionin free cash flow.

Shares of Sirius rose more than 3 percent to $2.71 inafternoon trading on Wednesday.

Karmazin was one of several executives from Liberty'sbusinesses presenting outlooks, including book retailer Barnes &Noble Inc , concert promoter Live Nation EntertainmentInc , and premium pay-TV network Starz LLC, which itplans to spin off into a separate public company.

(Reporting By Jennifer Saba; Writing by Peter Lauria; Editingby Gary Hill)

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