NBC has renewed “The Office,” “30 Rock” and “The Biggest Loser” for another season.

It also says “Heroes” (starring Ali Larter) has a “very secure” future.

“We have to have the quality and have to have the ratings,” said NBC exec Angela Bromstad.

“But we won’t replace shows that are loved by fans and are good quality shows just to put another show on.”

She gave a vote of confidence to “Heroes,” which has gone from one of NBC’s top-rated shows to approaching worrisome ratings territory.

” ‘Heroes’ is very secure,” she said.

But Bromstad said “Kath & Kim” (Molly Shannon) and “Knight Rider” are “shows that may or may not come back.”