He may usher in a new-look NBC this fall, but entertainment prexy Robert Greenblatt is sticking with the laffers that have provided an oasis of stability on Thursday nights for the Peacock.

In his first major move affecting next season’s primetime sked, Greenblatt announced renewals Thursday for laffers “Community,” “Parks and Recreation” and “The Office.” While not too surprising,the pickups are a sign that the Peacock’s new entertainment chairman isn’t wiping the slate clean for 2011-12.

These three comedies are “all at the top of their game creatively,” he said.

Greenblatt praised the 9 p.m. pairing of “Office” and “Parks,” which is up 17% in adults 18-49 vs. last season. “Community” had a tougher row to hoe in the leadoff 9 p.m. slot against Fox’s “American Idol” and CBS’ “The Big Bang Theory” but has remained a critical fave, along with “Parks.”

Pickup of NBC’s other Thursday mainstay, “30 Rock,” was secured in November, prior to Greenblatt’s arrival, when NBC decided to gamble on moving the show into the 10 p.m. slot. Since it made the move in January, “30 Rock” has improved the Peacock’s perf in the timeslot and been competitive with ABC’s “Private Practice” in the demo.

The exclusion of NBC’s frosh comedies “Outsourced” and “Perfect Couples” from Thursday’s renewal announcement doesn’t bode well for them, though their survival likely hinges on how many promising comedies emerge from development.

While the trio of renewed half-hours will likely remain on Thursday next season, Greenblatt has yet to tip his hand on whether NBC’s three-hour “Comedy Night Done Right” block will be back next season.

He could conceivably try to build a new comedy block outside Thursday; that might mean an established skein like “30 Rock” or “The Office” could be tapped to move as a lead-in to a new half-hour on another night.

Should the three-hour block remain, it could open a terrific opportunity or two for the 12 half-hour pilots vying for a spot on the 2011-12 schedule.

The renewals dim the prospects for several half-hours produced prior to Greenblatt’s arrival still waiting for a primetime berth. “Friends With Benefits” and an untitled Paul Reiser project may be held for summer runs, though no official decision has been made.

The “Parks” renewal seemed assured with the news Wednesday that NBC Universal Domestic Television Distribution was shopping the comedy for syndication (Daily Variety, March 17).