Chita Rivera, playing Roxie Hart in the Las Vegas sitdown of Chicago for the past three months, will leave the Glitter Gulch staging July 4 to prepare for her appearance in the London production.

Her first London date, at the Adelphi Theatre, is expected to begin Aug. 16. Her co-star is Valarie Pettiford, who is leaving Broadway's Fosse July 18 to play the U.K. Velma Kelly.

Rehearsals for the London Chicago begin July 28.

On July 6, Marilu Henner steps into the role of Roxie in Las Vegas, at the Mandalay Bay Resort. Ben Vereen and Marcia Lewis are still on board as Billy and Mama Morton, respectively.

Tickets are on sale for the Vegas show through at least November. *

Rivera, who turned 66 Jan. 23, 1999, was originally expected to continue in the Vegas stand to Aug. 28. She appeared in the original Broadway staging of Chicago in 1975 as Roxie's pal, Velma, singing "All That Jazz," which has become something of a signature for her.

Rivera's in-process one-woman show, backed up by "boy" dancers, is called Chita and All That Jazz. It had a summer 1998 tryout in Atlantic City and is expected to resurface perhaps in late 1999 or early 2000. Fred Ebb is a consultant.

The role of Roxie Hart, one of a gaggle of murderesses in the cynical musical comedy, was originated by Gwen Verdon in 1975.

Rivera made her splash as the original Anita in West Side Story in 1957-58 and over the next four decades appeared in Broadway musical hits and beloved flops, including Bye Bye Birdie, Kiss of the Spider Woman, Bajour, Merlin, Bring Back Birdie, The Rink, as well as in numerous club acts and tours (such as Can-Can).

For ticket information, call (702) 474-4000 or (877) 632-7400. The top ticket price at Mandalay Bay is $82.50.