WBC lightweight world champion Manny Pacquiao believes he can achieve boxing immortality by beating 10-times world champion Oscar De La Hoya in a bout billed as the "Dream Match".

Pacquiao, of the Philippines, who has captured world titles at four different weight divisions, takes on Los Angeles native De La Hoya in Las Vegas on Dec. 6.

"This is the biggest fight in my boxing career," Pacquiao, 29, told reporters.

"This is the door (through which) the name of Manny Pacquiao will be known, not only in the Philippines but in boxing history."

The bout is a 12-round, non-title fight contested at the 147-pound welterweight limit.

Although the 5 foot 6.5 Pacquiao concedes a four-inch height advantage, the Filipino feels his speed will be decisive.

"I feel very comfortable at that weight," he said.

Pacquiao's trainer Freddie Roach, who has produced 22 world champions, predicted the 35-year-old De La Hoya would not last the pace.

"You look at the history of boxing when the older guy fights the younger guy, like when Ali fought Holmes or when Joe Louis got beaten by Rocky Marciano," Roach told Reuters.

"It's the younger man's time. I don't think Oscar will be able to keep up and I think we will knock him out in the late rounds."

Roach knows De La Hoya's style well, having trained him for last year's super welterweight showdown with Floyd Mayweather Jr.

De La Hoya lost on a split decision and he and Roach parted on bitter terms.