A bittersweet irony is on the verge of becoming a boxing reality. Simon Brown and Maurice Blocker, who are best friends, are poised to sign to fight for two versions of the welterweight championship on March 18 in Las Vegas.

Brown and Blocker, who grew up together in Adams Morgan and now are neighbors in Germantown and both have 33-1 records, would meet on the Mike Tyson-Razor Ruddock card at The Mirage, Brown said yesterday.

Hard-punching Brown, 26, holds the International Boxing Federation welterweight title. He has defended it seven times, and most recently in December knocked out little-known Ozzie O'Neal in the first round of a nontitle bout.

Blocker, 27, won the World Boxing Council version of the title Dec. 8 in Reno when he upset Marlon Starling on a split decision. Brown always wanted to fight Starling to avenge an early-career defeat and move closer toward unifying the title.

"Now my best buddy has the title I've fought so long to get," Brown said. "I'm just going to put it out of my mind that he's my friend. It won't take me long to do that. This is a job that both of us have to do.

"I want to knock him out quick. I want to get it over with as quickly as possible and get on with our friendship. I don't want it to be a bad thing for him, something he would think about for the rest of his life.

"But this is something I've worked for for years. Starling kept dodging me. And now it just happens that my friend has what I want. The friendship is going to be extra incentive."

Brown would not reveal the terms of the contract he hopes to sign this weekend. But he indicated it would be for more money than either he or Blocker has ever fought for. "I'm going to win," Brown said, "but at least both of us will walk away happy."

The Mirage card is being promoted by Don King, and although Brown said he has not signed a contract with King, he has been moving in that direction. Blocker is managed by Butch Lewis, who recently said he was "throwing down the gauntlet" in an effort to get Blocker into the same ring with Brown for a good payday.

Blocker said recently that he was certain he would beat Brown if they met in a fight that counted; Lewis predicted "a hell of a fight."