BALTIMORE, AUG. 7 -- Brian Lee Tribble was ordered held without bond today after federal authorities here described him as a major cocaine dealer who might flee prosecution if freed on bail.

Tribble, acquitted three years ago of supplying the fatal dose of cocaine to University of Maryland basketball star Len Bias, was ordered detained by U.S. Magistrate Daniel E. Klein Jr. on drug-conspiracy charges.

Federal agents said Tribble fled the scene of an undercover drug operation at a Prince George's County hotel Thursday night but turned himself in Monday. Tribble, 27, who runs an upholstery business and lives in Forestville, has been the object of periodic interest by the FBI and the Drug Enforcement Administration since Bias's death in 1986.

At today's detention hearing, prosecutors characterized for the first time the scope of Tribble's alleged drug activity, saying he has distributed nine to 22 pounds of cocaine a month in the Washington-Baltimore area. Tribble has engaged in a "consistent pattern of trafficking . . . for a substantial period," Assistant U.S. Attorney E. Thomas Roberts said.

Drug enforcement agent Bill Simpson said later that nine to 22 pounds a month is "definitely large-scale {trafficking} for this area." Agents said a drug dealer cooperating with authorities allegedly agreed to sell Tribble 8.8 pounds of cocaine for about $100,000 as part of Thursday's undercover operation.

Roberts said agents searched Tribble's home Thursday and discovered "cooking paraphernalia" for converting cocaine to crack, as well as evidence of cocaine packaging.

In arguing for detention, Roberts said that a "lieutenant" of Tribble's, Ricardo Bernard Smith, was convicted of cocaine possession in Alexandria federal court this year and sentenced to 18 years in prison. Tribble has reason to flee because he knows he faces a substantially higher sentence if convicted, Roberts said.

Klein brushed aside pleas by defense attorney Thomas C. Morrow for bail or home detention for Tribble. Morrow noted that Tribble voluntarily surrendered to authorities Monday and said he has "intensely close ties" to his family.

Drug enforcement agents said Tribble fled from the parking lot of the Sheraton Hotel in New Carrollton Thursday as agents moved in on a transaction between the undercover supplier and an alleged Tribble accomplice.