Michael Spinks has relinquished his light heavyweight titles and will concentrate on defending his International Boxing Federation heavyweight championship.

Spinks, 29, who upset Larry Holmes Sept. 21 to win a heavyweight crown, had been undisputed light heavyweight champ since 1983. He held the World Boxing Council, World Boxing Association and IBF light heavyweight titles.

"Michael's immediate plans are to defend the heavyweight title in February," promoter Butch Lewis said. "Negotiations have started with Holmes, (Gerry) Cooney and all the other guys in the top ten who call every five minutes." Cooney said in an interview with Lancaster, Pa., station WGAL-TV that he is coming out of retirement and is close to signing for a title bout with Spinks in Lancaster . . .

Former champion Mark Kaylor twice got up from knockdowns to knock out Errol Christie in the eighth round of a scheduled 12-round bout to win the British middleweight title eliminator in Wembley, England.

After the boxers came to blows at a news conference last month, police, fearing increased racial tension in the wake of mob violence in London, asked that the fight not be held. Boxing officials refused. Kaylor is white and Christie black; both said there was nothing racial about their scuffle. There were no disturbances among the 10,000 spectators.

Christie was floored by a solid right to the jaw after 35 seconds, then sent Kaylor down with a short right. Kaylor was down again in the third round, but took command and ended the fight with a left-right combination to earn a shot at the British title held by Herol Graham.