Charter Communications shares shot up 5.9% to a 52-week high this afternoon after Bloomberg reported that it’s in talks to buy Bright House Networks, a cable company owned by Si Newhouse’s Advance Publications. It could take more than $12 billion in stock to land Bright House’s 2.5 million subscribers — concentrated in Florida, California, Michigan.

The companies probably will wait to see what happens with Comcast’s deal to buy Time Warner Cable before deciding whether to proceed. Charter’s top shareholder, Liberty Media’s John Malone, has said that he’d like the company to bid for TWC if federal officials thwart the Comcast merger. He has also said that, if Comcast and TWC combine, then Charter would have the financial wherewithal to go after smaller companies.

Bright House “has a reputation for being extremely well run, and it has – almost uniquely among cable MSOs – a strong reputation for service and customer satisfaction,” MoffettNathanson research’s Craig Moffett says.

Bright House’s prospects are clouded by its close relationship with TWC. The No. 2 cable company negotiates most of its programming carriage deals and has first dibs on Bright House following the break-up of their partnership in 2003. Moffett says that if TWC’s deal with Comcast collapses, and it wanted to fend off Charter, then taking on debt to buy Bright House “could be the ideal way to do so.”

But it’s unclear whether the collaboration might cause a problem in Washington for Comcast: If the TWC deal goes through, then the cable giant has agreed to unload 3.9 million subs to Charter and a new co-owned company. Comcast wants to assure federal regulators that, after a merger, it would serve less than 30% of all pay TV subscribers — which used to be a ceiling for one company. It’s not clear whether the Bright House customers would count in that tally.