Billionaire John Malone's Liberty Media said Thursday that it will convert nearly half of its preferred shares of Sirius XM Radio into common stock and nominate a slate of candidates to the company's board, as part of its ongoing push to take control of the satellite radio company.

Liberty Media said in a filing with the U.S. Securities and Exchange Commission that the common stock shares stemming from the preferred stock conversion, along with the stock it already holds or has agreed to buy, will constitute a stake of about 46 percent of the company.

The Englewood, Colo.-based company said in the filing that it will continue to buy shares of Sirius XM Radio's common stock on the open market, which could eventually allow it to replace Sirius' board by itself and take control of the company.

Liberty also said Thursday that it re-filed its petition with the Federal Communications Commission, asking it to reconsider its request to be awarded "de facto control" of Sirius within 30 days.

The FCC dismissed Liberty's application earlier this month, saying its application was "defective" partly because it did not establish that it intends to take actions that would give it full control.

In the meantime, Liberty said it will nominate candidates to the company's board that, if elected, will make up the majority of the board and give Liberty control.

Earlier this month, Liberty said it would spend $650 million to buy 302 million Sirius shares and boost its effective stake in the New York-based company to 45.2 percent. That deal is expected to close early in the third quarter.

If Liberty converted all of its preferred shares, it would own about a 40 percent stake in Sirius. The company saved Sirius from near-bankruptcy in 2009 by agreeing to lend it up to $530 million in exchange for the preferred stock.

A spokesman for Sirius didn't immediately return a call seeking comment.

Liberty shares fell 47 cents to $83.23 in morning trading, while Sirius shares rose 2 cents to $1.91.