Sugar Ray Leonard, training in Houston for his June 25 junior middleweight title bout with Ayub Kalule, says he's unperturbed by fight promoter Bob Arum's comments that he can't win and yesterday predicted he will beat the Uganda-born Kalule in 10 rounds or less.

"With this humidity, I wouldn't want the fight to go more than 10," Leondard said in a telephone interview.

In town last week to hype the fight, set for the Astrodome in Houston, Arum said, "I think It'll go down as one of the biggest blunders in boxing history. . .I'm somewhat sorry this Leonard-Kalule fight is taking place."

Saturday in Boston, after the Marvin Hagler-Vit Antuofermo middleweight title fight, Arum repeated his prediction that Kalule will beat Leonard in the 15-rounder.

"Everybody has his own particular opinion. I won't knock it," Leonard said.

Leonard added that moving up a division to a 154-pound limit has caused no problems "because my street weight is 152 or 154, anyway." He dismissed statements that Kalule's size would be too much for him.

"They said I would lose my speed with the extra weight, but I haven't. I feel great, really great," said Leonard, 25, the World Boxing council's welterweight champion who trained for the fight in Phoenix before coming to Houston.

Next week's card, billed as the "Welterweight Astrowars," pits Leonard, of Palmer Park, against Kalule, the World Boxing Association's junior middleweight champion, and World Boxing Association welterweight champion Thomas Hearns, the 22-year-old Detroit "Hit Man," against Pablo Baez.

Kalule, 27, has a 36-0 record with 18 knockouts and has done most of his fighting recently in Denmark. He was a member of the 1976 Ugandan Olympic boxing team and might have fought Leonard at those Games in Montreal were it not for the boycott by many black African countries that year.

Leonard said he is concentrating on next week's fight, giving little thought to his long-awaited showdown with Hearns in September.

Hearns, who has bristled at his bout with Baez being scheduled as a preliminary to the Leonard-Kalule match, is expected to receive $5 million for the September fight while Leonard has reportedly been promised $8 million, with the two fighters to split any portion of revenues in excess of $21 million.

Hearns, undefeated in 31 bouts, with 29 knockouts, has long sought a fight with Leonard, but Mike Trainer, Leonard's lawyer, put off any agreement until he could get what he said he thought the fight was worth.

For the Kalule fight, Leonard said, he expects to net "one or two big ones" (million dollars).

Beyond Hearns, Leonard said, his plans are uncertain, although a Leonard-Hagler fight at some future date appeared more of a possibility after Hagler's fifth-round technical knock-out of former middleweight champion Antuofermo Saturday.

In the past, Leonard has said he would like to fight Hagler, although that would mean a jump in weight to the middleweight maximum of 160, six pounds more than the junior middleweight maximum and 13 pounds more than the 147-pound welterweight limit.

Hagler, with 52-2-2 recorn, has long been bitter that fighters like Leonard have been able to rise more rapidly to title status and big money fights than he has. Hagler earned a reported $500,000 for his title defense last Saturday and both he and his manager, Goody Petronelli, say they would like nothing better than a fight with Leonard.