"I swear it to God and to everybody," Alexis Arguello declared, "that this will be my last fight."

The Nicaraguan expatriate--his confiscated home in Managua is now the Soviet embassy--was speaking in Las Vegas as his Friday night WBA welterweight title rematch with Aaron Pryor drew nigh.

"I will put the last drop of my blood into this fight," said Arguello--while, in Nicaragua, where Arguello is blacklisted as anti-Sandinista, any news of the fight is available only on the sly.

Pryor--whose own retirement talk is taken less seriously--is favored, 2 1/2 to 1, in Vegas to win in a 13,000-seat outdoor arena . . . Jimmy the Greek makes it 25-1 against Scott Frank taking Larry Holmes' WBC heavyweight title Saturday night in a 5,000-seat tent in Atlantic City . . .

Jose Correa, the Latin Connection (D.C.) trainer, reports his star welterweights Maurice Blocker (14-0) and Simon Brown (16-0) honing for upcoming Atlantic City bouts. Blocker is set against Philadelphian Kevin Howard in October; Brown may get Roger Stafford, once Stafford shakes off last weekend's quick TKO by WBA champ Donald Curry . . .

Jose Sulaiman, WBC chief, cites the ring death of bantamweight Kiko Bejines as case in point for the 12-round title bout limit imposed by his group. He says Bejines was obviously fatigued when Alberto Davila got to him for the fatal knockout--in the 12th. Sulaiman said the WBC will compensate the Bejines family $100,000.