Liberty Media's (Nasdaq: LMCA) first 40% chunk of Sirius XM Radio (Nasdaq: SIRI) was a door prize. The next chunk is going to cost it plenty.

Citigroup analyst Jason Bazinet is starting to believe that Liberty Media may be eyeing an 80% stake in the satellite radio company.

He's still in the minority. Most think Liberty Media will either stand pat or perhaps increase its stake to 50% once restrictions expire next week. However, Bazinet is eyeing the juicy net operating losses that Liberty Media could use to offset its own pre-tax profits as a majority stakeholder.

And, let's be fair -- Sirius XM has appreciated strongly in each of the three past years. Every trend must end, but the last thing that Liberty Media wants to do is see Sirius XM appreciate to the point where it doesn't have any option but to potentially cash out to cash in, mother of all tax bites and all.

For those a little fuzzy on the dark days of early 2009, Sirius XM was on the brink of bankruptcy. EchoStar's (Nasdaq: SATS) Charles Ergen and Liberty's John Malone figured it would be better to save the satellite radio giant than duke it out in bankruptcy proceedings, so both offered the financing that Sirius XM direly needed.

Sirius XM went with Malone. In exchange for letting Sirius XM borrow the money at a hefty 15% interest rate, Liberty was given a 40% preferred share stake. It has proven to be quite the bonus. Liberty's stake is worth a cool $6 billion these days.

As you can probably imagine, taking a majority stake in Sirius won't come cheap. Liberty would need to shell out a $6 billion investment to double its stake, and that's if it doesn't have to pay too princely a premium.

I wonder how Warren Buffett feels about satellite radio. Berkshire Hathaway (NYSE: BRK-A) (NYSE: BRK-B) recently acquired 1.7 million shares of Liberty Media, apparently just in time for the fireworks that may begin as early as next week.

Interesting times, indeed.

Running of the bulls
I remain bullish on Sirius XM's future. It should come as no surprise that I'm promoting the CAPScall initiative for accountability by reiterating my bullish call on Sirius XM for Motley Fool CAPS.

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