"I'm being hired by the British government to consult with them on the issue of gangs, gang violence and gang intervention from the American experience and to offer some advice and counsel on their experience," Bratton told Reuters.
Bratton, chairman of the Manhattan-based private security firm Kroll, called the post a "short-term assignment" to help Britain develop strategies on dealing with widespread rioting and gang culture.
"I'm not joining the British government," he said. "I'm not moving there. I'll be there several times, certainly."
The final terms and conditions of the arrangement were still being discussed, he said.
Cameron called Bratton directly on Friday, seeking advice after looting, arson and violence swept London and other cities this week, triggered after a man was shot dead by police last Saturday in north London.
"The government is very interested in trying to quickly come up with strategies and plans to deal with the issues and concerns identified during these riots," Bratton said.
In Los Angeles, where Bratton was police chief from 2002 to 2009, he helped quell gang violence and improve strained relations with the community.
The law enforcement strategies applied in Los Angeles were "transferable and modifiable" in Britain, he said.
"In America, particularly in Los Angeles, we've been dealing with gangs for, in some instances, almost 80 years," he said. "Particularly in Los Angeles, we've had a lot of success dealing with gangs and the violence."
After hearing on Thursday that Cameron had singled out his law enforcement accomplishments, Bratton said in a statement he would be honored to counsel British authorities on calming street violence.
Bratton has teamed up with British police at other times over the past 20 years. In 2009, Queen Elizabeth II awarded him the honorary title of Commander of the Most Excellent Order of the British Empire.
A native of Boston, Bratton headed that city's police department in the early 1990s and initiated a neighborhood policing effort to reduce violence among young people.
As New York police commissioner under former Mayor Rudy Giuliani, Bratton implemented a "zero tolerance" crackdown on street crime that ushered in a period of record crime reduction.
Bratton said he had been interested in the vacant post of Commissioner of the Metropolitan Police in London but that "unfortunately" that job was only open to British citizens.