(Reuters) - Charter Communications Inc (>> Charter Communications, Inc.) said its acquisition of Time Warner Cable Inc (>> Time Warner Cable Inc), which is awaiting clearance from U.S. regulators, is now expected to close in the first quarter of 2016, and not by the end of 2015 as planned.

The $56 billion deal, announced in May, is subject to intense regulatory scrutiny as the combined company would control a big swath of the U.S. cable and Internet market.

"Realistically, we think we're looking at a first-quarter close," Charter Chief Executive Tom Rutledge said on a call on Thursday to discuss the company's third-quarter results.

The deal has been approved by the shareholders of both companies and most U.S. states, but is awaiting clearance from the U.S. Department of Justice and the Federal Communications Commission (FCC).

"From an operational perspective, we are working to be in a position to close as early as this year, but admittedly at this point that feels ambitious," a Time Warner Cable executive said on a post-earnings call, declining to provide details.

National Association of Broadcasters and Dish Network Corp (>> DISH Network Corp) have separately petitioned the FCC to reject the proposed merger, which Dish said would be no better for public interest than Comcast's proposed deal.

Comcast Corp (>> Comcast Corporation) dropped a $45 billion bid for Time Warner Cable in April after regulators raised concerns that the deal would give the market leader an unfair advantage.

The delay in closing the deal came as no surprise to analysts at MoffettNathanson and Evercore ISI. Charter also has a better chance of closing the deal than Comcast did, they said.

"The magnitude and depth of opponents to this transaction was substantially lower than on the Comcast-Time Warner Cable transaction," Evercore's Vijay Jayant said. He said the deal could close by March if everything went to plan.

STRONG EARNINGS

Shares of Time Warner Cable and Charter were up 2.5 percent and 3.6 percent, respectively, in midday trading on Thursday after both companies posted strong third-quarter results.

Time Warner Cable posted a better-than-expected adjusted profit as, on a net basis, it added more high-speed data customers than expected and lost fewer net video subscribers than feared.

While the company is benefiting from rising demand for high-speed internet services, it stemmed video subscriber losses by offering "triple play bundling" services, combining pay-TV, high speed data and voice.

Charter swung to a quarterly profit, also helped by its Internet business, as well as a $142 million tax benefit.

(Reporting by Anya George Tharakan and Sai Sachin R in Bengaluru; Editing by Savio D'Souza)

By Anya George Tharakan and Sai Sachin R