The celebrated tenor Jon Vickers will open next year's Handel Festival at the Kennedy Center in the title role of Handel's Old Testament oratorio "Joshua."

It will be Vickers' debut with the Handel Festival and the organization's Washington premiere of "Joshua."

Stephen Simon, the festival's music director and conductor, announced this and other details of the group's 11th season here during a press conference yesterday at the Kennedy Center.

*The Handel Festival specializes in concert performances of Handel operas and oratorios, many of them unjustly neglected until the ongoing Handel revival.

Vickers, a Canadian, has been best known over his long career for his command of Wagnerian tenor roles and the heavier Verdi roles. But in recent years he has diversified his singing, into such different characters as Benjamin Britten's Peter Grimes and some Handel parts.

This season the Metropolitan opera staged for Vickers an operatic version of the oratorio "Samson," only the second Handel production in the Met's history.

"Joshua" will be done next Jan. 18. Among the other singers: mezzo Carolyn Watkinson, soprano Lorna Haywood and bass Jan Opalach.

On March 2 will come the Washington premiere of Handel's last opera, "Deidamia," with mezzo Tatiana Troyanos in the title role. It is about the Trojan War. Other singers: soprano Benita Valente, soprano Jane Marsh and soprano Linda Mabbs.

The season will conclude on May 3 with another of the "Hallelujah Handel!" variety programs that are becoming a custom. Popular arias will be mixed with choruses and instrumental works.

Among the soloists: soprano Judith Blegen, tenor Rockwell Blake, countertenor Drew Minter and organist Anthony Newman.