On Wednesday, Sirius XM Radio Inc (NASDAQ:SIRI) raised its guidance for a subscriber increase to 1.8 million this year, up from its prior 1.6 million forecast.

 Sirius XM

The company also said it added almost 446,000 subscribers through the quarter ending in September. Through the end of this period, Sirius had a record 23.4 million subscribers, reported the Associated Press, representing its top third quarter since its 2008 merger with XM.

To-date, Sirius XM Radio Inc (NASDAQ:SIRI) has 1.5 million additional subscribers with 87 percent of the company’s revenues coming from subscriptions in the first half of 2012.

The company also said it should conclude the year with approximately $3.3 billion in revenue, and about $700 million in free cash flow.

The company’s update had been announced by Sirius CEO Mel Karmazin during remarks at Liberty Media Corp’s (NASDAQ:LMCA, LMCB) annual investor day. Liberty is Sirius’ biggest shareholder with a stake at almost 50 percent. It initially purchased a 40 percent share in the company back in 2009, through a transaction that included a loan of $530 million to help prevent a bankruptcy filing.

But for months, Liberty has been interested in full control of the company and has gone as far as to file a petition with the U.S. Federal Communications Commission, and to ask that the company’s board be replaced.

Liberty also believes Sirius needs to be more aggressive about going after improved technology and broadening its reach internationally.

As for Karmazin’s future with the company, he did not give any clues in his presentation on whether or not he’ll stay, or if Sirus will give him an extension when his contract expires at the year’s end. The question was not posed by analysts after the numerous executive presentations.

Karmazin has been known to dislike working for a “controlling shareholder,” reported Reuters, and he has said he won’t be hanging around if there’s a shift of control by Liberty, and if  John Malone has anything to do with it.

This could not be a good thing, as in addition to increasing subscriber numbers, under Karmazin’s leadership, Sirius has also said it has an estimated 70 percent market share in the U.S. for new cars sold. The executive has also had a hand in negotiating new contracts for key talent, including  Howard Stern.

Sirius is looking to expand through possible acquisitions, and just this week, Karmazin noted the company reviewed four companies. He said via Reuters, “There is nothing out there we have seen that is appropriate for the company to do.”

Instead, Karmazin said the company’s stash of cash could go to its shareholders but that is a board decision.

With the updated company numbers, Sirius XM Radio Inc (NASDAQ:SIRI) shares increased more than 3 percent on Wednesday and closed up 4.56 percent to $2.75.