The Games are scheduled to begin Feb. 4.
The request came from human rights groups who said they opposed China’s treatment of minorities, including Uyghurs, Tibetans, Hong Kong residents and others, The Associated Press reported.
The letter accuses NBC and the other networks of "being complicit" in China’s human rights abuses, the AP reported.
The groups sent a letter Tuesday to Jeff Shell, chief executive of NBC Universal, as well as the heads of other networks around the world that have broadcast rights to the Games, the AP reported.
NBC’s planned coverage is part of a $7.75 billion deal struck with the International Olympics Committee (IOC) for coverage of the next six Olympiads, the report said.
Separately, the IOC is facing calls to boycott Beijing, including pressure from 15 major sponsors of the Games, according to the AP.
A vice president with Intel, a California-based tech company that is an Olympics sponsor, has claimed that he agrees China is guilty of "genocide."
Other broadcasters being asked to cancel coverage include Canada’s CBC, Britain’s BBC and Germany’s ARD, the AP reported.
Human rights groups signing the letter include International Tibet Network, World Uyghur Congress, Free Tibet, China Against Death Penalty, WeTheHongKongers and Keep Taiwan Free.
The Associated Press contributed to this story.