July 31 (Reuters) - Comcast Corp posted a higher quarterly profit on Wednesday, as it added more Internet customers than expected on the cable side and saw a more than 20 percent increase in operating cash flow at its NBC Universal unit.

Its shares rose more than 6 percent in morning trading to $45.30 on the better-than-expected results.

Analysts said Comcast's cable business outperformed in what is generally a seasonally weak quarter for the industry, when colleges close for the summer and people disconnect cable service ahead of a move.

"The second quarter is always tough for the cable business. But you'd never know it from Comcast's second-quarter results," Moffett Research analyst Craig Moffett said. "This consistency speaks to the tight ship Comcast is running these days."

Comcast's cable unit, which has the most U.S. subscribers of any cable company with 21.7 million, added 187,000 high-speed Internet customers on a net basis. This beat analysts' expectations of 150,500 additions, which Wall Street was expecting, according to StreetAccount.

Comcast, like its smaller rivals, increasingly relies on Internet customers for growth as they continue to lose cable TV subscribers and grapple with rising programming costs.

Comcast lost about 159,000 video subscribers in the quarter, which slightly beat estimates of a loss of 159,700 subscribers, according to Street Account.

The cable industry faces a challenge from customers who consume an increasing amount of Internet video and subscribe to lower-cost alternatives such as Netflix.

Comcast clinched full control of NBC Universal for $16.7 billion earlier this year by buying out General Electric's stake a few years ahead of schedule. It owns broadcaster NBC, the film studio Universal and a host of cable channels. While the unit is viewed by Wall Street as a perennial money loser in need of a turnaround, it made money for Comcast in the second quarter.

Operating cash flow at NBC Universal rose 21 percent to $1.191 billion, driven by the box office performance of the action movie "Fast and Furious 6" and a strong quarter at its cable network units, which oversees channels such as Bravo, E! and the Golf Channel.

Chief Executive Brian Roberts said NBC Universal has "real momentum, with solid growth in revenue and double-digit cash flow growth."

NBC also generated $2.1 billion in advance sales for commercial time for the upcoming TV season after wrapping up the so-called "upfront" negotiations. NBC confirmed on Wednesday it secured 7 to 8 percent increases in ad rates above last year.

Wunderlich Securities analyst Matthew Harrigan said NBC Universal's performance beat his estimates, partly driven by broadcast network ratings, which benefited from the return of hit singing show "The Voice" in the second quarter.

"On the TV side you can really see a benefit in primetime ratings at NBC and a 13 percent increase in advertising revenue, which was more than people had modeled," he said.


In July, Comcast's movie studio Universal signed Thomas Tull, the founder of film production company Legendary Entertainment that made big-budget blockbusters such as "The Dark Knight" and "Man of Steel", luring him away from rival Warner Brothers.

NBC Universal CEO Steve Burke said on Thursday that the deal "will take a while to get moving." He said Legendary will make its own films that Universal can co-finance, while Legendary will also co-finance some Universal movies.

"On the big film side, the riskiest and in some ways the hardest part of the business right now, we will have a partner in Legendary that has a real passion for that," Burke said.

Comcast posted a second-quarter profit of $1.73 billion, or 65 cents a share, compared with $1.3 billion, or 50 cents a year ago.

It beat Wall Street analysts' estimates by 2 cents, according to Thomson Reuters I/B/E/S.

Revenue rose 7 percent to $16.27 billion. Analysts, on average, expected $16 billion.

Second Quarter 2013 Highlights

Consolidated

• Revenue increased 7.0% to $16.3 billion and Operating Cash Flow grew 8.4% to $5.4 billion. Operating Income increased 11.6% to $3.4 billion.

• Free Cash Flow increased 25.4% to $1.9 billion, reflecting growth in consolidated operating cash flow and improvements in working capital, partially offset by higher taxes and capital expenditures.

• Comcast returned $1.0 billion in capital to shareholders, including dividends totaling $514 million and the repurchase of 12.6 million of its common shares for $500 million.


Comcast Cable

• Total Video, High-Speed Internet and Voice customers increased by 189,000. This is a 36.8% increase compared to Q2 2012 net additions, reflecting growth in High-Speed Internet and Voice customers, and reduced losses in video customers. As of June 30, 2013, Video, High-Speed Internet and Voice customers totaled 52.1 million, an increase of 1.6 million, or 3.1%, over last year’s second quarter.

• High-Speed Internet (HSI) customer additions were 187,000. We now have just under 20 million HSI customers with more customers receiving higher speed services.

• Video customers decreased by 159,000, a 10% year-over-year improvement compared to Q2 2012. We have deployed our X1, cloud-enabled platform to more than half of our footprint and we are on track to have it available nationwide by year end. We now have 21.8 million Video customers.

• Voice customer additions were 161,000, compared to 158,000 additions in Q2 2012. We now have 10.3 million Voice customers.

• Business Services revenue increased 26.4% to $788 million during the quarter as we attracted customers in the small and mid-size markets.

• Cable Advertising revenue increased 1%. However, when you exclude the impact of last year’s political revenue, our core cable advertising revenue grew by 5%.


NBCUniversal

• Broadcast Television revenue increased 11.6% to $1.7 billion compared to $1.6 billion in Q2 2012, driven by a 13.0% increase in advertising revenue, primarily reflecting higher primetime ratings at the NBC broadcast network, and higher retransmission consent fees, partially offset by lower content licensing due to the timing of content availability.

• Cable Networks revenue increased 7.7% to $2.4 billion, reflecting a new content licensing agreement, a 4.4% increase in distribution revenue and a 5.7% increase in advertising revenue.

• Filmed Entertainment revenue increased 12.8% to $1.4 billion, driven by higher theatrical revenue from the strong box office performance of Fast and Furious 6, as well as higher content licensing revenue from the availability of certain films in international television markets.

• Theme Parks revenue increased 1.1% to $546 million reflecting the shift of the holidays to the first quarter this year.