White is the 37-year-old president of the mixed-martial arts promotion company that has become a heavyweight in the pay-per-view business. Ortiz (15-5-0) is one of its toughest, most popular combatants.

Ortiz made the three-round match — in which both fighters will box only, no grappling — a condition of his recent contract negotiations.

White was once Ortiz' manager, but the two "had a real bad falling out" in 2003, White said.

"The last time Tito and I boxed was six years ago, and he's a lot better than he was six years ago," White said after a hearing at the Nevada Athletic Commission, which approved the fight 3-1. "I'm a lot older than I was six years ago, so we'll see."

Regulators expressed concern that White would be seriously hurt by Ortiz, 32.

But most commissioners were reassured by sparring tapes showing White in the ring against another heavyweight from two months ago. White said he's been training since last July.

"I've seen Tito as a boxer, and he's probably not as good as you are," commission chair Dr. Tony Alamo told White.

Ortiz will weigh in at 205 pounds, while White weighs 196 pounds, both the boxing equivalent of heavyweight fighters.