World heavyweight boxing champion Muhammud said yesterday he does not think he will be able to speak at Harvard Class Day ceremonies on June 11, as planned.

All, who agreed to be Class Day speaker two weeks ago, said he was told by his manager. Herbert Muhammud, that he will have to leave for Kuala Lampu. Malaysia by June 9. He is defending his title there on June 28 against Joe Bugner.

Peter Carfagna '75, a member of the Class Day Committee, said last night that Muhammud had called the committee yesterday afternoon with the news that Ali probably would not speak.

The committee has not yet received final word from Ali.

Ali said yesterday at a news conference, "My mananger Herbert Muhammud says I might not be able to go. He says the fight's more important." Ali had said the topic of his speech was to be. "The Intoxication of Life."

Ali could not be reached for comment last night.

Carfagna said as soon as Ali's cancellation is confirmed, the Class Day Committee will extend an invitation to journalist Hunter Thompson, who had been their fourth choice as Class Day speaker.

Carfagna said Thompson had earlier expressed "a great desire to speak at Harvard at any time" and added that he was "confident that he'll come, even at this late date."

Thompson writes for Rolling Stone Magazine and a spokesman for the magazine said last night she doubted Thompson would be able to come to Harvard since he was working under a deadline on an article. Thompson returned from a two month stay in Sargen earlier this month.