Marc Connelly, who wrote the Pulitzer Prize-winning play "The Green Pastures" and who was for years a major creative force in the Broadway theater, died Sunday in a hospital in New York. He was 90.

An actor, director and producer as well as a playwright, Mr. Connelly was for decades one of those who helped to create and perpetuate the tradition of the New York stage as one of the most literate and polished forms of mass entertainment.

A hearty, outgoing and gregarious man who believed in the ability of the theater to evoke wonder and produce delight, Mr. Connelly was noted also as a wit and raconteur. He belonged to the famed Algonquin Round Table, a gathering of celebrated New York writers and wits named for the hotel where they met.

Regarded by many as one of the great works of the American stage, "The Green Pastures" opened on Broadway Feb. 26, 1930, won wide acclaim from audiences as well as critics, and ran in New York for 640 performances. It grossed about $3 million in depression-era dollars.

After Braodway the play ran for hundreds of performances on tour and was made into a successful motion picture.

Once described as having achieved the status of an American folk legend, "The Green Pastures" was based on "Ol' Man Adam an' His Chillun," a book of short stories published in 1928.

The play presents the Biblical stories of the Flood and of Moses and Joshua in what was purported to be the way these stories might be interpreted by a black preacher and his flock on a plantation in the South. On stage, a black God presides over a black heaven. A chorus sung spirituals during changes of scene.

Although the play was lauded by its many admirers, who saw it as a work of humane and genuine compassion and understanding, there were signs that it did not age well.

A 1951 revival on Broadway ran for little more than a month and encountered complaints that it perpetuated outmoded sterotypes.

In an interview given in 1968, Mr. Connelly said he was "afraid that for the present, racial pride would count against "The Green Pastures' and its innocent, childlike (remember now, not childish, childlike) characters."

Known for years as one of the Grand Old Men of the American theater, Marcus Cook Connelly was born Dec. 13, 1890, at McKeesport, Pa., where his parents, both actors in a touring stage company, had bought a hotel and settled a year earlier.

The hotel was a way-station for traveling troupes and performers, and it was in this atmosphere, surrounded by the traditions of the stage, that young Marcus grew up.

A 1908 fiscal panic bankrupted the hotel and canceled Mr. Connelly's college plans. He was a newspaperman in Pittsburgh, but worked after hours with amateur theatrical groups.

In 1916 he moved to New York to hear a song, for which he had written the lyrics, performed in a Broadway play.The play closed quickly, but Mr. Connelly lingered in New York, finally landing a job on a newspaper, for which he covered the theater district.

Mr. Connelly met George S. Kaufman, then also a young newspaperman covering Broadway, and the two began to collaborate on plays of their own.

The first, "Dulcy", starred Lynn Fontaine, then just making her American reputation. It opened on Broadway on Aug. 13, 1921, and was the season's first hit.

Mr. Connelly and Kaufman followed with several other plays, including the hit "To the Ladies," the popular comedy "Merton of the Movies," which opened in 1922, and "Beggar on Horseback" in 1924.

The two men's collaboration as playwrights ended before "The Green Pastures," but their friendship continued.

After being carried on stage at the rousing conclusion of the hit play, Mr. Connelly began an impromptu speech.

"Years ago," he said, "George Kaufman and I made a pact. If either of us ever dared address a first-night audience, the other was privileged to open fire immediately with an elephant gun.

"Mr. Kaufman happens to be sitting on the aisle in row B. I bid you good night."

Mr. Connelly, who began directing on Broadway in 1926, also served stints as a Hollywood screenwriter.A founder of the New York magazine, he wrote numerous magazine articles as well as short stories, one of which, "Coroner's Inquests" won the 1930 O. Henry Prize.

He also taught playwriting at Yale, lectured widely on the craft, was a founder of the Dramatists' Guild, published his memoirs and a novel, a work of comic suspense called "A Souvenir from Qam."

A string of occasional acting appearances began in 1944 when he played the stage manager in a 1944 revival of "Our Town" at New York's City Center. A stocky, bald-headed bespectacled man, he portrayed a college professor on Broadway in 1959 in "Tall Story" and in the 1960 film version of the play.

"Every playwright should act," he said, "It is a way of improving his own craft.""

Mr. Connelly's marriage in 1930 to Madeline Hurlock ended in divorce five years later.