ARTS PANEL WAITS IMPATIENTLY FOR ITS NEW CHAIRMAN.(MAIN)

Byline: DIANE HAITHMAN - Los Angeles Times

Waiting.

White House insiders say President Clinton has already chosen a candidate for chairman of the National Endowment for the Arts but plans to wait to reveal his nominee until after returning from his international summit trip to Tokyo, followed by two days in Seoul, Korea, and several days' vacation in Hawaii.

The favored candidate, according to rumors, at this point is actress Jane Alexander, currently starring on Broadway in Wendy Wasserstein's play "The Sisters Rosensweig." Alexander's press representative, Susan Chicoine, said: "She has no comment at this point -- until something is …