General Motors has decided to end its sponsorship of the CBS hit series "Survivor" screened in the US but said the decision had nothing to do with the reality show's controversial decision to divide its contestants in the upcoming season by race and ethnicity.

GM spokeswoman Ryndee Carney told The Associated Press (AP) the company made the decision in the normal course of making its media buys months ago, before the show made its recent announcement.

"I think it's just a coincidence. I know it's not cause and effect," Carney reportedly said.

The news agency noted that a group of New York City officials have criticised the new format, saying it promotes divisiveness, and have asked CBS to reconsider its plans.

Show creator Mark Burnett reportedly said that many of those criticising the new approach haven't ever seen the show and don't understand how it works.

"By putting people in tribes, they clearly have to get rid of people of their own ethnicity," he told The Associated Press. "So it's not racial at all."

For the first portion of the 13th edition of "Survivor," which premieres on 14 September, the contestants competing for the $US1m prize while stranded on the Cook Islands in the South Pacific will be divided into four teams - blacks, Asians, Hispanics and whites.

GM, which has sponsored "Survivor" since it premiered in May 2000 and was the show's exclusive automotive sponsor, is shifting some of its media dollars from prime-time television to more live sports, awards shows and other big events, Carney told the news agency.

The Detroit-based company also decided that its media strategy should feature cars and trucks integrated into shows, which was difficult on "Survivor," she said.

Although one episode did feature a Pontiac Aztek, the opportunities for cars and trucks on the show were few, Carney told AP.

"There's a limited number of possibilities as to how you can integrate a car or truck in a show that people spend their whole time on an island," she added.

CBS spokesman Chris Ender told AP GM notified the network of its decision long before the new "Survivor" format was announced. He said the company had no knowledge of the competition by race.

Like GM, other advertisers will move more toward integrating their products into shows as more viewers use technology such as digital video recorders to avoid watching commercials, Robert Thompson, professor of television and popular culture at Syracuse University, told the Associated Press.

"Advertising is going to have to go back to the early days of television when you had products integrated into the shows themselves," he said.

While he doesn't expect it to happen within five years, the single-spot commercial might eventually disappear, Thompson added, according to the report.