Boxing's three major governing bodies have ruled that the winner of the Evander Holyfield-Buster Douglas heavyweight bout must fight former champion Mike Tyson, a spokesman for promoter Don King said yesterday in New York.

John Solberg said King has received letters from the International Boxing Federation, the World Boxing Association and World Boxing Council to the effect that Tyson is next in line for a title shot after Douglas tries to defend the championship against Holyfield Thursday in Las Vegas.

Douglas won the title when he knocked out Tyson Feb. 11 in Tokyo.

A settlement of breach-of-contract suits by Douglas and King also calls for Douglas to fight Tyson if he beats Holyfield. Holyfield's people have said that, if he wins, he will defend against former champion George Foreman. . . .

Holyfield has been sued for divorce. His wife said in Atlanta she wants a response by Thursday, the day her husband bids for the undisputed heavyweight championship.

"I'm hoping that when the fight is over with, we'll be able to amicably resolve this," said Paulette Holyfield, the fighter's wife of five years and mother of their three children.

The papers had been filed Sept. 10, but had been kept private. . . .

Kevin Rooney, Tyson's former trainer, won the first round of his breach-of-contract lawsuit against Tyson when a federal judge in Albany, N.Y., denied a motion for dismissal of the case.

U.S. District Court Judge Con Cholakis's denial means the suit will go to a jury trial in early 1991, according to Megan Kuntze, Rooney's spokeswoman.

Rooney filed the suit a year ago, claiming Tyson broke a contract that said Rooney would train Tyson for as long as the heavyweight remained in boxing.