Clyfford Still, 75, a painter whose bold and jagged abstractions made him one of the major figures in American art after World War II, died Monday at Mount Sinai Hospital in Baltimore. He had cancer.

A man who was often called "eccentric" and "cantankerous," Mr. Still pursued an independent course in the art world. He eschewed art dealers and gallery shows in favor of exhibitions at major museums. As a result, his work is less widely known than that of such contemporaries as Jackson Pollack, Willem de Kooning and Robert Motherwell.

Mr. Still's paintings are represented in most major collections of modern art in this country and abroad. They are in the National Gallery of Art, the National Collection of Fine Arts, and the Hirshhorn and Phillips collections in Washington. The largest exhibition of his work was held at the Metropolitan Museum of Art in New York last year.

"The paintings should be permitted to speak for themselves," Mr. Still once said.

His mature canvases, monumental in size, are wholly nonfigurative. There are thickly painted areas of intense color that intersect with jagged lines and black often plays a dominant role.

In "The Triumph of American Painting," the critic Irving Sandler wrote of Mr. Still:

"His pictures suggest that he deliberately renounced painterly graces, sensuousness and sophistication: the forms are ragged, looking at if they are arbitrarily drawn: the colors are dry and repeated in unrefreshing sequences; and the surfaces, consisting of paint trowelled on with palette knife, are scabrous. In sum, these canvases, while elating, are nevertheless rude and dour."

For Mr. Still, however, his work was not bleak.

"I choose that my art be engaged in that which exalts the spirit of man," he wrote in a note about a painting of his that was included in the inaugural show at the Hirshhorn. "To memoralize in the instruments of art the banal attritions of daily experience that are common to nearly every individual appears to me to be of small virtue. It may give morbid pleasure to the viewer or reader, and profit to the artist, but it remains an exercise in degradation. Who seeks such satisfactions in my work will find little to reward his attention."

Of black, which he so often used to dramatic advantage, and sometimes exclusively, Mr. Still once said, "Black was never a color of death or terror (for me). I think of it as warm and generative."

Mr. Still's influence as a teacher and painter became a significant force in American art after his meeting with Mark Rothko in California in 1943. The two are credited with stimulating what is known as "the San Francisco Renaissance."

"He offered the first alternative to cubism that the new generation could take seriously," wrote the British critic Kenneth Sawyer.

The artist himself vigorously -- and characteristically -- rejected what he called "the well-madeness and prettiness" of cubism, which he saw as a symbol of Western European decadence. With the passage of the years, Mr. Still's work also came to be seen as a major inspiration of the Washington color painters.

Clyfford Still was born on a farm near Grandin, N.D., on Nov. 30, 1904.

He grew up on his father's homestead at Bow Island, Alberta, Canada, and at the family home in Spokane, Wash., where his father was an accountant.

He began painting while still a small child, taking time from farm chores to do it and ignoring the fact that his family considered that artists were "sissies." He later obliged his parents by signing his paintings only with his first name and not with the family name.

Mr. Still earned bachelor's and master's degrees at the University of Washington. Having completed his education, he declined to join the WPA artists project as so many of his contemporaries did. Instead, he was an instructor and then a professor at Washington State University from 1935 to 1941.

During World War II, he drew blueprints for the aircraft and shipbuilding industries in the Oakland and San Francisco area, and it was there that he met Rothko. In 1950, he moved to New York City and joined the community of artists that became the center of innovation in the postwar period. The innovation was abstract expressionism.

In his years in the West, Mr. Still painted realistic landscapes. By the early 1940s, he was peopling them with distorted figure studies -- bony, angular men and bloated women. These paintings were exhibited in his first one-man show, which was held at the San Francisco Art Museum in 1943.

"By 1941," Mr. Still withdrew from New York to the reclusive isolation of a farm at New Windsor, Md., 30 miles outside Baltimore. In 1964, however, he donated 31 of his paintings to the Albright-Knox Gallery in Buffalo, N.Y. They were valued at $1 million.

Mr. Still's survivors include his wife, Patricia, and two daughters, Sandra Still, of New York City, and Diane Rocha, of San Francisco.