Jean Stapleton, Liv Ullmann and Alan Arkin, starring in such works as "The Late Christopher Bean," "Ghosts" and "The Imaginary Invalid," will be part of a six-play series which the Kennedy Center will produce in partnership with CBS/Broadcasting Group, beginning mid-December.

The plays, announced yesterday by Roger L. Stevens, the Kennedy Center's chairman, mark the first step toward the creation of a resident company in the Eisenhower Theater and represent the Kennedy Center's most ambitious theatrical undertaking since it produced nine plays for the Bicentennial under the banner of the American Bicentennial Theater.

CBS has contributed $600,000, two-thirds of the estimated $900,000 it will cost to mount the plays, each of which will have a six-week run. (In addition, Stevens announced plans for a revival of "Medea," the expenses of which will be borne by the Kennedy Center alone.) Most of the plays will be produced under a League of Resident Theaters (LORT) contract, similar to that which governs such regional theaters as the Tyrone Guthrie Theater in Minneapolis and the Mark Taper Forum in Los Angeles.

The series is set to open the week of Dec. 14 with a revival of Friedrich Durrenmatt's "The Physicists," which had an unsuccessful run on Broadway in 1964. The sardonic drama focuses on three nuclear physicists incarcerated in a madhouse and examines the question of personal responsibility in a world that has the capacity to destroy itself. Brian Bedford, Len Cariou and Irene Worth will star under Stephen Porter's direction.

Stapleton will appear in late January and February in "The Late Christopher Bean," Sidney Howard's comedy about the members of a crusty New England family who once befriended an artist and discover, after his death, that his canvases are worth a fortune. Stapleton has already played in the work at the Totem Pole Playhouse, the summer theater she and her husband, William Putch, operate in southern Pennsylvania. Putch will direct the 1932 work for the Kennedy Center.

It will be followed in March by a revival of the Robinson Jeffers version of Euripides' "Medea," with Zoe Caldwell as the scorned Medea and Dame Judith Anderson (who played Medea in the original Broadway production) taking the role of the nurse. Not part of the CBS-financed plays, the Greek tragedy will have only a five-week run and will be directed by Robert Whitehead, Stevens' longtime producing partner in New York.

Moliere's "The Imaginary Invalid," directed by Gene Saks and starring Alan Arkin as a hypochondriac who wreaks havoc on his family, will open toward the end of April. Ralph Allen, the Kennedy Center's theatrical productions consultant who has helped plan the season with Stevens, has prepared a new adaptation of the classic French comedy.

Liv Ullmann will be Mrs. Alving in "Ghosts," Ibsen's celebrated drama which shocked audiences in 1881 with its then-frank discussion of venereal disease. Playwright Arthur Kopit will do a new translation and Zoe Caldwell will probably direct it for a June opening.

Stevens said he is also negotiating for two contemporary plays as part of the CBS package. One will open in late July and the other will be part of the Kennedy Center's 1982-83 season.

The cost-saving decision to produce the plays under a LORT contract will allow actors to appear in one play at night while rehearsing a second during the day. Just how many actors would stay on from production to production, thereby forming the nucleus of a resident company, is yet to be determined. "I would expect a few," said Stevens, who also hopes to name resident scene and costume designers. Contracts for stars, whom Stevens feels are mandatory for successful revivals of classic works, will not surpass $2,500 weekly. "The money certainly isn't anything for them to come here for," he explained. "But strangely enough, some of these people actually like to act."

Under the terms of its agreement with CBS, the network will contribute $100,000 to each of the six productions, while the Kennedy Center will provide $50,000. The Kennedy Center will produce the plays for Washington only, although "The Late Christopher Bean" is already set for a Broadway engagement under the auspices of producer/actress Martha Scott. Otherwise, the first-class rights -- for Broadway, television, cable or movies -- would have to be negotiated independently by an outside producer. However, the Kennedy Center could realize a small profit by selling its physical productions, sets and costumes to that producer.

CBS' financial commitment does not automatically guarantee it rights to the productions and the network would have to negotiate them like anyone else. Asked to explain his corporation's interest in the series, Gene F. Jankowski, president of CBS/Broadcasting Group, said, "The theater is a natural extension of the business we're in. We are always on the look for fresh ideas that might find their way into television. But that's not the primary reason. We think this partnership is worthy of and by itself." CBS, however, has already taken an option on the Broadway rights to "The Physicists," and Stevens acknowledged that the alliance gave CBS "a foot in the door" in any future negotiations.

Jankowski said that the $600,000 contribution comes out of CBS' operational expenses and is not considered a philanthropic gift. The sum represents the approximate cost of a made-for-television movie.