Stan Wojewodski Jr., the artistic director of Center Stage in Baltimore, will succeed Lloyd Richards as artistic director of the Yale Repertory Theatre and dean of the prestigious Yale School of Drama, both Center Stage and Yale University announced yesterday. Wojewodski, who has been with Center Stage for 15 years, will take over the position from Richards on July 1. Richards has held the post for 12 years, two years longer than is customary for a Yale dean to serve. Wojewodski's initial term will run until 1996.

Wojewodski came to Center Stage in 1975 after completing his graduate studies at Catholic University. He has been artistic director since 1977. He came on just as Center Stage moved into its present quarters on Calvert Street, and he immediately began introducing more risky and modern material into what had been a repertory consisting mostly of classics and chestnuts. For the first time, the works of such writers as Peter Handke and Jean-Claude Grumberg, hardly boffo box office, were performed. Wojewodski also made a commitment to new playwrights such as Russell Davis and Eric Overmeyer. Next month he will direct the premiere of Overmeyer's "The Heliotrope Bouquet by Scott Joplin & Louis Chauvin" in Center Stage's new "black box" theater.

Since Robert Brustein founded it 25 years ago, the Yale Rep, in New Haven, Conn., has established itself as one of the outstanding nonprofit theaters in the country. During Richards's tenure it hosted premieres by such writers as Athol Fugard and August Wilson.

Wojewodski will be only the third person to hold the Yale position. Brustein, whose departure was acrimonious, is currently artistic director of the American Repertory Theatre and a Harvard English professor. He said yesterday he considers Wojewodski's appointment "a superb choice" and is "very impressed that Yale has chosen someone from the nonprofit theater."

The search committee for Richards's successor was formed in January 1990. Garland Wright, artistic director of the Guthrie Theatre in Minneapolis and a former artistic associate at Arena Stage, is said to have been a serious contender for the position. Wright had no comment yesterday.

Wojewodski, 42, said he looks forward to "the challenge of integrating the work of a theater with that of a drama school." In a sense, he's been preparing for this for years: "Certain people, when they go to graduate school, begin to evaluate what it was like, for better or worse. I guess I'm one of those."

He prefers not to speculate on why Yale settled on him: "I'm not willing to stretch my modesty that far ... or deflate my ego that much." Though he says that leaving Center Stage is a "very difficult" decision, he feels proud that he and Managing Director Peter W. Culman have made Center Stage a "very important center for ongoing work in the theater."

A search committee for Wojewodski's successor has been assembled but has not met formally.