Willy T. Ribbs, the first black driver to enter the Indianapolis 500, withdrew yesterday, hours after his first practice laps at Indianapolis Motor Speedway.

He cited a lack of time to prepare his new March-Cosworth and his unfamiliarity with the car and his team. Wednesday, Ribbs signed a two-race deal to drive for Indy car owner Sherman Armstrong and boxing promoter Don King.

"We felt it was best for everyone if I made my Indy-car debut at the Meadowlands (U.S. Grand Prix) race" on June 30, said Ribbs, a veteran Trans-Am driver. "Of course, I am disappointed, but for everyone involved, I need more time to familiarize myself with the car and this team.

"Expecting me to come in here and do as well as we want to do is like getting me a pair of boxing gloves one morning and telling me I'm supposed to fight Muhammad Ali that night."

Ribbs, 29, of San Jose, Calif., arrived at the track for his first practice run Friday afternoon, but the car wasn't ready. He finally got onto the track yesterday morning.

Qualifying is May 11-12 and May 18-19 for the May 26 race.