The FCC is trying to turn up the heat on Cablevision and Fox to resolve the retransmission dispute that has kept Fox’s Gotham and Philadelphia stations off of Cablevision systems since Oct. 16.

Meanwhile, both sides lost a bargaining chip when the Texas Rangers ended the New York Yankees’ quest for a World Series berth in Friday’s Game 6 of the American League Championship Series.

Barring a big breakthrough in the next 48 hours, it appears that the standoff could extend through Wednesday’s start of the fall classic, which airs on Fox. The pressure to get WNYW and WWOR New York back on the air for Cablevision’s 3 million subscribers would only have increased had the Yankees made it to the Series.

The FCC has asked both companies to provide written explanations of their negotiating strategies to prove that they are operating in good faith, as called for in the law governing retransmission consent deals between broadcasters and subscription TV providers.

William Lake, chief of the FCC’s media bureau, sent a letter Friday to Cablevision prexy-CEO James Dolan and to News Corp. chief operating officer Chase Carey seeking the info by end of business today.

“We ask each of you to describe to us how your company is satisfying this important statutory obligation in the context of your retransmission consent negotiations,” Lake wrote. “In particular, we request that you describe with specificity what has transpired since you initially began your negotiations, and detail the efforts your company is making to end the current impasse. If you are aware of any conduct by the other side that you believe violates the good faith requirement, please so indicate and provide supporting evidence.”

Cablevision and numerous lawmakers have been pressing the FCC to intervene or mandate that the sides go to binding arbitration, though others doubt whether the commission has the legal standing to do so. It does have the ability to fine companies who violate the good-faith clause.

Lake’s letter follows a statement from FCC Julius Genachowski last week that criticized both companies for “spending more time attacking each other through ads and lobbyists” than negotiating. Cablevision and Fox execs have not held face-to-face negotiations since Oct. 18, though they have had brief telephone conversations.

Despite the entreaties from the FCC and dozens of pols, the sides appear to be digging in their heels. Fox execs are also said to be slightly distracted by stepped-up carriage negotiations with satcaster Dish Network. Dish dropped FX and 19 regional Fox sports networks on Oct. 15 in a contract fight with Fox, and a Sunday deadline looms for the national sat-TV provider to renew its retrans deals for Fox’s 27 O&Os. If not, Fox may find itself fighting a retrans war on two fronts.

“We welcome the FCC’s intervention,” said Charles Schueler, Cablevision’s exec veep of communications, of Lake’s letter. “Whether through FCC action, binding arbitration or any other means, the time has come for News Corp. to end the Fox blackout of 3 million Cablevision households.”

Fox said it would respond to the FCC by today but had no further comment on the FCC’s move. On Friday Fox called for Cablevision to issue rebates to its customers for the duration of the blackout.

“After all, these customers have lost the National League Championship Series, the NFL on Fox and a full week of Fox’s primetime shows due to Cablevision’s refusal to negotiate,” Fox said.