On the heels of series-record ratings for “NCIS” on Tuesday, CBS has renewed the drama series for a ninth season and cut a new two-year pact with star Mark Harmon.

Harmon’s deal calls for him to be upped to exec producer status on the show. His Wings Prods. shingle has also inked a development pact with “NCIS” producer CBS Television Studios.

News of the pickup for the 2011-12 season comes as the show delivered a boffo 22.9 million viewers in its Tuesday 8 p.m. airing, matching its series high in adults 25-54 (6.5 rating/16 share) and delivering its best 18-49 score (4.6/12) since 2009. For the season to date, “NCIS” is averaging 19.6 million viewers and 4.2/11 in adults 18-49, making it primetime’s No. 2 drama in the demo behind ABC’s “Grey’s Anatomy”; it’s the No. 1 drama in both adults 25-54 and total viewers.

“It’s simply amazing that a show in its eighth season continues to perform at such an elite level,” said CBS Entertainment prexy Nina Tassler. CBS TV Studios topper David Stapf noted that the show is a “top performer in territories around the world.”

Harmon has headed the ensemble cast of the procedural revolving around officers of the Naval Criminal Investigative Service since its debut in 2003. A successful spinoff, “NCIS: Los Angeles,” bowed last season.

Harmon joins Shane Brennan, Gary Glasberg, Chas. Floyd Johnson, Mark Horowitz and Donald P. Bellisario as exec producers on the series. Michael Weatherly, Cote de Pablo, Sean Murray, Pauley Perrette, Rocky Carroll and David McCallum are co-stars.

Harmon is repped by Paradigm and attorney Barry Axelrod.