Sieber replaces Tom Wopat as slick lawyer Billy Flynn. Wopat played his final performance in the Tony-winning revival June 16. Sieber's return marks his second stint as Flynn; he will stay with the Broadway cast through Aug. 1.

On Broadway Christopher Sieber has been seen in Thoroughly Modern Millie, Into the Woods, Triumph of Love and, currently, in Chicago. His other theatrical credits include Boys in the Band, A Christmas Carol, Pal Joey, The Music of Andrew Lloyd Webber and Meet Me in St. Louis. Sieber’s television credits include “Two of a Kind,” “Sex and the City,” “Ed,” “All My Children,” “Another World” and “It’s All Relative.” Sieber will also be part of this year's Broadway Bares fundraiser June 20.

The Chicago company currently stars Tracy Shayne as Roxie Hart, Brenda Braxton as Velma Kelly, P. J. Benjamin as Amos Hart, Roz Ryan as Matron "Mama" Morton and R. Bean as Mary Sunshine.

Chicago won the Tony for Best Revival of a Musical in 1997 as well as awards for actors Bebe Neuwirth and James Naughton, director Walter Bobbie, lighting designer Ken Billington and choreographer Ann Reinking. The original production was directed and choreographed by the late Bob Fosse.

The Ambassador Theatre is located at 215 West 49th Street.