CBS has given its nerd sitcom "The Big Bang Theory" an unusual three-year renewal, which will carry the show through the 2013-14 TV season.

"Big Bang Theory," now in its fourth season, is the key of CBS' aggressive push into Thursday comedies, an arena traditionally dominated by NBC. The show has taken some ratings heat in moving from Mondays to Thursdays this year but it has helped CBS raise its Thursday numbers. This season, the comedy is averaging 13.9 million viewers, according to the Nielsen Co., which is up 7% in the time slot.

Created by Chuck Lorre and Bill Prady, "Big Bang Theory" stars Johnny Galecki and Jim Parsons as two science geniuses; Kaley Cuoco is their attractive neighbor.

"It doesn't take a theoretical physicist to see why this show is a big part of our comedy future," CBS Entertainment President Nina Tassler said in a statement.

What do you think? Are you up for three more years of "Big Bang"?

-- Scott Collins (Twitter: @scottcollinsLAT)

Photo: Jim Parsons in "The Big Bang Theory." Credit: Monty Brinton / CBS