BOSTON — DRUG agents confiscated more than 2 tons of cocaine with a street value of $500 million in the largest seizure of the drug in New England history and third major bust this summer, authorities said.The 4,822 pounds of cocaine had a street value of $500 million, according to US Attorney Wayne Budd. Ten people were arrested, eight of them Colombian nationals, and five vehicles with secret compartments were confiscated with $600,000 in cash and cashier checks. "The drug traffickers know their business, but we know ours," said Mr. Budd, who credited the success Sept. 2 to "real dedicated pros" and to the cooperation among federal, state, and local law enforcement agencies. An undercover informant aided the United States Drug Enforcement Administration (DEA), the Immigration and Naturalization Service, the US Attorney's Office, and several police departments in coordination with the US Customs Service on the case. "This is the biggest seizure in New England history," said Pat O'Malley, spokesman for the US Customs Service. Budd said the three seizures in Massachusetts this summer totaled nearly 5 tons of cocaine worth about $1 billion on the street. The suspected ring-leaders were arrested Aug. 31 in Wakefield, Mass., at a hotel where buyers and distributors met to consumate their deal, Budd said. He declined to say where the drugs originated because the investigation is continuing. Officials also declined to detail how undercover agents came into possession of the shipment Aug. 7 in Norwood, Mass., but said it was kept in a secret facility while the ring-leaders negotiated with buyers. The investigation into the drug-smuggling conspiracy began in the fall of 1990 and culminated Aug. 31 with the arrests at the Colonial Hilton Hotel in Wakefield when the buyers and distributors arrived with money and vehicles. Officials identified the ring-leaders named in indictments as Marcos Garzon of Bogota, Colombia; Climaco A. Pedraza of Miami; Marco A. Gomez of Miami; and Robert Reister, no hometown available. Mr. Garzon and Mr. Gomez were arrested Aug. 31 at the Colonial Hilton and Mr. Pedraza at his Miami home. Mr. Reister remained at large. All were charged with conspiracy to possess cocaine with intent to distribute. If convicted, the suspects face up to life in prison and fines.