LOS ANGELES (REUTERS).- A soon-to-be-auctioned Beatles contract for a 1965 California concert reveals that the Fab Four took a firm stand in support of the era's civil rights movement, refusing to play before a segregated audience.

The contact, which is signed by the Liverpool group's manager, Brian Epstein, specifies that they "not be required to perform in front of a segregated audience" for their August 31, 1965, show at the Cow Palace in Daly City, California.

The document will be auctioned on September 20 by Nate D. Sanders in Los Angeles.

The Beatles took a public stand on civil rights in 1964, during their first American tour, when they refused to perform at a segregated concert at the Gator Bowl in Jacksonville, Florida. City officials relented, allowing the stadium to be integrated, and the band did take the stage for that show.

The Cow Palace concert was part of the Beatles' third major tour of the United States.

Signed on March 24, 1965, the contract guaranteed the band $40,000 against gross box office receipts of more than $77,000.

In addition to the desegregation requirement, the agreement called for at least 150 uniformed police officers for protection and a special drumming platform for Ringo.

The contract is estimated to sell between $3,000 and $5,000.

(Reporting by Sheri Linden; Editing by Jill Serjeant)