The highest-ranking Soviet diplomat to defect to the United States, Arkady Schevchenko, is in a dispute with his publisher over a contract that promised him a pre-publication advance of $600,000. Now Simon and Schuster -- for reasons the publisher will tell neither Schevchenko nor anyone else -- doesn't want to publish Schevchenko's memoir under the present terms of the deal. And it wants the approximately $140,000 already paid to Schevchenko returned.

The former diplomat, meanwhile, is putting the finishing touches on his book's 33 chapters that detail his life in Soviet officialdom and his subsequent decision to defect in 1978, thus becoming the CIA's catch of the decade. Shevchenko currently lives here with his second wife, a Washington woman he married last year. And according to his lawyer, Shevchenko is eager to find another, more enthusiastic, publisher. h

"Shevchenko is dissatisfield with his treatment from Simon and Schuster," says William Geimer, the former diplomat Washington lawyer. Geimer says S&S head Dick Snyder and editor Michael Korda seemed pleased by the early chapters of the books they read last year. "But then calls were not returned, and they seemed paranoid about Judy Chavez's revelations."

In the fall of 1978, a Washington callgirl named Judy Chavez charged publicly that she'd been paid $5,000-a-month in CIA funds to provide sex for Shevchenko. The former diplomat and the CIA denied the funds were from government coffers. But the ensuing publicity, says Geimer, devastated Shevchenko.

Neither Snyder nor Korda of S&S would comment on what could become a precedent-setting and openly messy fight between a publisher and a famous author unable to learn why his manuscript is unacceptable.

Footnote: Most important to Shevchenko, says attorney Geimer, is a public understanding that the CIA is not involved in the book project, an assertion jeopardized earlier this year when a CIA agent phoned a literary agency to enlist aid in finding another publisher for the defector-turned-author.

"Shevchenko reacted with horror when he learned a friend in the CIA had made contact," says Geimer. "He wants to make it clear that he is not under the thumb of any government. This is the first time that this guy is free, free to speak his mind without any government interference." The CIA agent was asked to curtail his literary efforts on Shevchenko's behalf. c