Sugar Ray Leonard will fight Wilfredo Benitez for the world welter-weight championship on Saturday night, December 1, it was announced yesterday, and the Palmer Park, Md., contender said, "I have reached a goal.

"This is a chance to prove myself to the people who have been wondering about the quality of my opponents. I'll be satisfied and the people who have been supporting me will be. This makes up for all the time I have put into it."

The site has not been determined, but the title bout will be part of a prime-time doubleheader televised by ABC.

In the other bout, former ligt-heavy-weight champion Mike Rossman will meet the winner of Victor Galindez's upcoming title defense against Marvin Johnson.

The unbeaten Leonard will try to make it 23 straight Sunday in Las Vegas against junior middleweight Tony Chiaverini.

Asked if he were not taking a risk against Chiaverini, who is 29-3-1, with 20 knockouts, Leonard said, "No, I'll just learn more and be a better boxer from it. I'll probably have two other bouts before I meet Benitez."

Angelo Dundee, Leonard's manager said, "He can't think of risks. A guy could get hurt walking across the street. He's got to fight. Chiaverini is a left-hander and Benitez frequently shifts into a southpaw stance. Carlos Palomino lost his title to Benitez because he didn't know how to handle a left-hander."

Benitez has a tuneup, nontitle bout scheduled for July 20 against Johnny Turner in New York City.

Leonard watched the telecast of Benitez upsetting Palomino for the title January 14 in Puerto Rico and said yesterday, "Benitez made mistakes. I think I can beat his speed with mine and dominate him. The heat took its toll on Palomino that day and he was not in the best of condition. I will be in top shape."

Leonard has 13 knockouts since winning the gold medal for the United States in the 1976 Olympics.

Benitez has a 37-0-1 record, scoring Weston, then decisioned Weston in March.

Benitez is the World Boxing Council champion and Jose (Pepino) Cuevas is the World Boxing association titleholder.

If Leonard takes the WBC title from Benitez, Palomino will get the first shot at it. Palomino was guaranteed a rematch after losing to Benitez, but stepped aside for a consideration from Leonard. Palomino also realized that a Leonard-Palomino bout would draw better than a Benitez-Polomino bout.

Leonard is such an attraction that although the champion usually receives 60 percent of all revenues and the challenger 40 percent, Leonard will be paid much more than 60 percent for the December fight, according to Mike Trainer, Leonard's attorney.

It will cost about $2.5 million to cover Leonard's and Benitez' purses, so Leonard figures to earn upwards of $1.5 million.

"I can't say this is a dream from back when I boxed at the Police Boys Clubs, because that was the least thing in my mind then," Leonard said.

While he is in Las Vegas, Leonard said, he will be watching a closed-circuit telecast of Palomino's bout Friday night against former lightweight champion Roberto Duran in New York City.