Bishop John T. Walker, who heads the Episcopal Diocese of Washington and is identified with liberal and ecumenical causes, is one of four candidates nominated to become presiding bishop of the Episcopal Church in America.

Bishop Walker is the first black clergyman ever nominated to head the predominantly white American branch of the Anglican church, which has about 2.9 million members, according to a spokesman.

The election of the presiding bishop, who is the top cleric of the church, will take place in September at the church's general convention in Anaheim, Calif. The convention is held every three years.

Bishop Walker, 59, was installed in 1977 as the sixth bishop of the Washington Diocese and the first black to hold that post.

He has been a leading advocate for the poor on a variety of urban issues and is known for his work with leaders of other faiths, according to a spokesman for the church in New York City, which announced the nominees yesterday. He is also dean of the Washington Cathedral.

The spokesman said the other nominees are: Bishops Edmond Browning of Hawaii, a former missionary bishop; William Carl Frey of Colorado, a leading church spokesman on peace issues, and Furman Stough of Alabama, an urban affairs advocate and chancellor of the University of the South in Tennessee.

The nominations were made by a committee of bishops, priests and lay members of the church at a meeting this week in Dallas, the spokesman said. The presiding bishop will be elected by the approximately 180 bishops expected to attend the convention in September.

The new bishop will succeed the Most Rev. John Allin of Mississippi, who has served for 12 years.