Push is coming to shove at QVC, but the billion-dollar question -- Who will end up controlling the home shopping channel? -- is far from settled.

John Malone-led

Liberty Media

(L) - Get Report

, which owns 42% of the shopping channel, said Monday it had started the clock for transforming the ownership structure of QVC, the balance of which is owned by cable colossus

Comcast

(CMCSA) - Get Report

.

As the end of the process, QVC -- valued by Wall Street at north of $12 billion -- could end up in one of three new situations. The company could end up wholly owned by either Comcast or Liberty, or it could be sold off to a third party. In any case, a coming transaction stands to have a major impact on the media landscape. Liberty's sale of its QVC stake, for example, could strengthen a bid for direct broadcast satellite operator

Hughes Electronics

( GMH). On the other hand, a Liberty purchase of Comcast's stake would indicate a Hughes bid is unlikely.

In addition, any deal could have a major affect on Comcast's debt load -- which the company is attempting to reduce -- as well as on litigation between Liberty and Comcast related to certain programming costs.

On Monday, Liberty shares rose 36 cents to trade at $9.55, while Comcast's fell 51 cents to trade at $28.71. Shares in Hughes fell 7 cents to $10.12.

Fair and Balanced

Under the "exit process" or "exit rights process," as the relevant agreement between Comcast and Liberty is known, the two owners will attempt to agree on a fair market value for QVC by the end of March. If that process fails, they'll defer to a third-party valuation of the home shopping channel.

Once QVC's value is set, Comcast has 30 days to decide whether it wants to purchase Liberty's stake. If Comcast isn't interested in buying, Liberty has its own 30 days to decide whether it wants to buy Comcast's 58% stake. If Liberty isn't a buyer, either, the companies are required to use their "best efforts" to sell QVC, in which either company could again emerge as a buyer for the complete company.

Neither company has been forthcoming about whether it would rather be a buyer or seller -- Comcast chief Brian Roberts deflected a question about the issue on

a conference call with analysts last week.

Freedom

But Liberty's initiation of the process comes at a time when it would be more difficult than usual for Comcast to launch a bid. Given the hammering that Comcast and other cable stocks have taken over the past year, the company might be loath to use its shares as currency for making the purchase. And in the wake of its purchase of the former

AT&T

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cable systems, Comcast is seeking to reduce its debt and protect its credit rating. A debt-financed purchase of Liberty's stake would pose a challenge.

"They don't have as much freedom to buy now as they would a year from now," says Mark Greenberg, portfolio manager of the

( FLISX)Invesco Leisure fund, which holds both Comcast and Liberty stock.

But a Comcast purchase of Liberty's stake can't be ruled out. On its conference call last week, Comcast said it had $10.5 billion in lines of credit and nonstrategic assets to cover $3.2 billion in financing needs, leaving $7.3 billion theoretically possible for a QVC transaction. And those strategic assets don't include the 21% stake Comcast is expected to receive in Time Warner Cable.

Also playing into the transaction may be

separate litigation ongoing between Liberty and Comcast over the price Comcast is paying for programming from Liberty's Starz Encore Group. Comcast went to court over the issue days after its AT&T Broadband acquisition closed, seeking an out from a contract negotiated between Liberty and the AT&T systems when they were both controlled by John Malone.