Former “Ally McBeal” series regular Jane Krakowski is joining the cast of NBC’s new fall comedy “30 Rock.”

She has been hired to play the star of “The Girlie Show,” a network variety show that serves as the backdrop for the workplace comedy.

Ms. Krakowski replaces Rachel Dratch, who played the role in the “30 Rock” pilot. Ms. Dratch, a fellow cast mate on “Saturday Night Live” with “30 Rock” creator Tina Fey, will have a smaller role on the series by playing a variety of characters in multiple episodes.

“30 Rock” debuts on Wednesday, Oct. 11 at 8:30 p.m. (ET).

The series is produced by Broadway Video and NBC Universal Television Studio. “SNL” executive producer Lorne Michaels, JoAnn Alfano, Marci Klein, David Miner and Ms. Fey are executive producing “30 Rock.”