Dick Ebersol, the chairman of NBC Universal Sports, made the announcement during the United States Olympic Committee's Assembly in Colorado Springs.  

NBC's cable partners also will expand their coverage by 100 hours and average 50 hours a day.

NBC's network and cable partners broadcast a total of 3,600 hours during the 2008 Olympics in Beijing and 835 during the Winter Games in Vancouver earlier this year.

When NBC televised the Olympics for the first time - in Tokyo in 1964 - they showed a total of just 15 hours.

London will be the seventh consecutive Olympics that NBC has shown but is the last Games that they won as part of the record $2.2 billion (£1.3 billion) deal they signed with the International Olympic Committee (IOC) in 2003.

An NBC delegation earlier this month visited London for the first of what are set to be several operational meetings.

They plan to base up to 1,000 people in London during the Olympics, including camera crews, reporters, makeup artists, chefs, doctors and runners. 

The IOC has yet to begin negotiating for the United States television rights for the 2014 Winter Olympics in Sochi and the 2016 Games in Rio de Janeiro.

A fragile economic climate in the United States had prompted the IOC to delay the start of negotiations.

But Jacques Rogge, the President of the IOC, said last night that he expects negotiations to open before the end of this year.

"We will most likely start negotiations either at the end of this year or in the beginning of next year," Rogge told Associated Press.

"The economy is improving, and the economy is definitely the major factor for which we waited.

"Broadcasters in the United States are funded exclusively by advertising.

"We now see signals and we hear from our partners in the advertising world that advertising is coming up.

"So we are waiting for that to negotiate."

NBC will bid to keep the rights but face opposition from ABC-ESPN, CBS, Fox Sport and Turner, who Rogge expects to all bid.

"It's not going to be an easy discussion but there is good will on both sides to find a good solution," Rogge told Associated Press.

"We want to find a win-win solution in the long term."

Ebersol claimed that he is happy with the IOC decision to delay negotiations.

"You have no choice," he said.

"You go by what they say and when they want to do it.

"I have been so lucky for such a long period of time that I'm going to just keep rubbing my rabbit's foot."


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