Jose de Rivera, the internationally known sculptor whose sleek revolving "Infinity" stands outside the Smithsonian Institution's Museum of American History, died of pneumonia yesterday at Lenox Hill Hospital in New York City, according to hospital officials there. He was 80.

Mr. de Rivera had continued to work daily in his New York studio until he was hospitalized about five weeks ago, relatives said.

A curvilinear form that rotates atop a black granite pylon, "Infinity" was the first abstract sculpture on the Mall, and as such was controversial because it was not strictly representational, as original museum building plans had called for.

An "orrery" -- a skeletal globe used to demonstrate the movement of celestial bodies -- was planned for the space outside the museum's south entrance, and after officials selected Mr. de Rivera's work, architect Walker O. Cain insisted that it could be viewed as a "21st century orrery."

Mr. de Rivera preferred to leave those discussions up to others. In an interview with The Washington Post shortly before the piece was installed in 1967, Mr. de Rivera said he regarded the work as "just an abstract form."

"When I make an abstract sculpture, I give it an abstract name. Then they can discuss it all they want," Mr. de Rivera said.

Like the paradoxical Mobius strip, "Infinity" has only one external surface. Viewed from one angle, the sculpture resembles the symbol for infinity, and from another it looks like a circle surrounded by an ellipse.

The largest abstract sculpture commissioned by the government up to that time, "Infinity" was built by hand of stainless steel by de Rivera and fellow sculptor Roy Gussow. He was paid $104,520.

Sculptures by Mr. de Rivera were exhibited at World Fairs in San Francisco, New York (in 1940 and 1964), Seattle and Brussels, and other examples of his work are on display in the Smithsonian's Hirshhorn Museum and Sculpture Garden, the Museum of Modern Art, the Virginia Museum of Fine Arts in Richmond and the Whitney Museum of American Art.

Born in West Baton Rouge, La., in 1904, Mr. de Rivera studied drawing with John W. Norton in Chicago and later was associated with the Works Progress Administration Federal Art Project in New York.

He had taught at Brooklyn College and North Carolina State University's School of Design and had been a critic in sculpture at Yale .

Survivors include his second wife, the former Lita Jeronimo, whom he married in 1955, four grandchildren and three great grandchildren.