Kennedys suing over real estate trust

John and Caroline Kennedy have accused Barbra Streisand's brother of cheating them out of half their interest in a 20-year-old real estate trust established by their mother.

The allegations against Sheldon J. Streisand came to light in court papers he filed to block arbitration the Kennedys requested concerning his handling of the trust's money.The trust was established in June 1978 by Jacqueline Kennedy Onassis and owns 99 percent of a real estate investment partnership called Western Properties Associates Three. Streisand and his firm, Sheldon J. Streisand Inc., are general partners in Western, each owning one-half of one percent.

The Kennedys' demand for arbitration, in papers Streisand filed last week in state Supreme Court, does not disclose the total value of the trust, but it appears to be worth at least $1 million.

The Kennedys complained that Streisand sold 50 percent of Western to his wife for the "bargain price" of $500,000, "diluting (the Kennedys') 20-year-long interest in the partnership from 99 percent to 49 percent."

The Kennedys asked that Strei-sand and his company be ousted as general partners and replaced with partners' chosen by them.