Percy Heath, the superb bassist who for more than 40 years provided the sublime underpinnings for the Modern Jazz Quartet, died Thursday of bone cancer at a hospital in Southampton, N.Y. He was 81.

Mr. Heath was the last surviving member of the quartet he helped found that became known simply as the MJQ. Mr. Heath joined with pianist John Lewis, drummer Connie Kay and vibraphonist Milt Jackson, to create a restrained bop style that was considered the epitome of sophistication.

He and his brothers, saxophonist Jimmy Heath and drummer Albert "Tootie" Heath, made up one of the great families in jazz.

Percy Heath was born April 30, 1923, in Wilmington, N.C.

He was drafted into the Army in 1944, and learned to fly P-4s and P-47s as a member of the Tuskegee Airmen. His class graduated in early 1945. He saw no combat. After the war, he decided to go into music, so he took part of his military separation money and bought a stand-up bass.

Mr. Heath and his brother Jimmy moved to New York in the late 1940s. By 1950, they had found steady work with trumpeter Dizzy Gillespie.

The MJQ had its genesis in the Gillespie big band. As Lewis told critic Leonard Feather some years ago, he and three other band members — drummer Kenny Clarke, bassist Ray Brown and Jackson — decided to form a group to try to create a sound that was not based on the standard themes of the day.

The group originally was called the Milt Jackson Quartet. Mr. Heath joined the group when Brown left to play in his wife Ella Fitzgerald's band.

The Modern Jazz Quartet officially was born in 1952. After a well-received European tour, it returned home and slowly caught on with American fans. Kay joined the group in 1955 when Clarke moved to Europe.

The group was a popular fixture on the American jazz scene until it broke up in 1974. The split lasted until 1983, when they reunited for a highly lucrative series of concerts in Japan.

In addition to his brothers, Mr. Heath is survived by his wife, June, and his sons, Percy III, Jason and Stuart.