Robert Urich, who appeared as Billy Flynn in Chicago on national tour in Detroit and Washington DC, brings his tuxedo to Broadway for six weeks, beginning Jan. 5.

Urich, best known for his TV roles on "Vegas," "Spenser: For Hire" and "The Love Boat: The Next Wave," will sing "Razzle Dazzle" at the Shubert Theatre to Feb 13.

His co-stars in the acidic musical comedy about "merry murderesses" in Jazz Age Chicago are Sandy Duncan (as Roxie) and Mamie Duncan-Gibbs (as Velma). The revival's original Velma, Tony Award-winner Bebe Neuwirth, steps in Jan. 18, with Belle Calaway joining her, as Roxie.

The casting of this hugely popular "musical vaudeville" (its original billing) is as complicated as the show's comic plot twists. For the record: Duncan and Duncan-Gibbs exit Jan. 16, Brent Barrett returns as Billy Feb. 15, Tony-nominated Marcia Lewis remains as Matron Mama Morton.

* The 1975 John Kander-Fred Ebb-Bob Fosse musical became a smash hit in revival (1996 and still going), eclipsing the original respectable run (923 performances) in the mid 1970s.

The 1996 revival first starred Neuwirth as Velma and Ann Reinking as Roxie, playing roles originated by Chita Rivera and Gwen Verdon, respectively. Walter Bobbie directed, Reinking choreographed in the style of Fosse.

For information about Chicago, call (212) 239-6200.