MIAMI, SEPT. 26 -- Floyd Carlton Caceres, a convicted drug pilot who has become the government's star witness against Manuel Antonio Noriega, testified today that the former Panmanamian leader demanded $600,000 in payoffs from leaders of the Medellin cartel in exchange for authorizing him to fly planeloads of cocaine from Colombia into Panama.

During six hours of richly detailed testimony, Carlton, 42, described how Noriega repeatedly escalated demands for money from the cartel, scoffing at amounts offered by Colombian drug traffickers and becoming incensed when they attempted to operate in Panama without his permission.

"These people believe that we in Panama are a tribe of Indians and they can come in and do what they please," Carlton quoted Noriega as telling him angrily at one point.

Carlton's testimony was by far the most effective for the prosecution in Noriega's three-week-old trial for drug trafficking and racketeering. Until today, no prosecution witnesses had been able to tie Noriega directly to drug transactions, leading to speculation that the government's case was not as strong as advertised.

But the mood in the courtroom shifted quickly when Carlton, sporting a blue blazer and stylish haircut, began recounting repeated conversations with Noriega about payoffs and meetings Carlton had with Pablo Escobar, Gustavo Gaviria, Jorge Ochoa and other cartel leaders.

Carlton testified that Noriega almost never referred to drugs in their conversations. Nor did he mention Noriega's name, he said, to Escobar and Gaviria, referring to him only as "my associate" or the "man who authorized me to carry out these flights."

Between September 1982 and December 1983, Carlton said, Noriega authorized him to fly four planeloads of cocaine into Panama, with Noriega's cut starting at $100,000 and growing to $200,000 by the last. Carlton testified that Escobar would protest Noriega's escalating demands and once said of them, "Here we go again."

Carlton testified that he personally delivered the money to intermediaries designated by Noriega, corroborating testimony this week by former Noriega aide Luis Del Cid that he received envelopes stuffed with cash from Carlton and delivered them to his boss.

But, Carlton said, Noriega abruptly cut off the flights at the end of 1983 because he recently had become the chief of the Panamanian military and was concerned about his image. At one meeting, he said, Noriega told him that "under no circumstances did he want to be linked to the people in the Mafia."

Several times today, Carlton looked directly at Noriega and pointed to him while recounting comments that the former general allegedly made. In stark contrast to Del Cid, who avoided eye contact with Noriega during his testimony, Carlton looked squarely at Noriega when led into the courtroom late Wednesday and nodded.

Carlton's allegations, first made to Drug Enforcement Administration agents after his arrest in Costa Rica in January 1987, led to Noriega's indictment the following year. Shortly thereafter, he appeared before a Senate subcommittee with a black hood over his head.

Carlton testified that, after receiving a nine-year sentence in June 1988, he was released last year and is in the federal witness-protection program, receiving $1,200 a month in living expenses from the government. Courtroom artists were instructed not to depict his face today.

Questioned by Assistant U.S. Attorney Michael P. Sullivan, Carlton described how he and Cesar Rodriguez, his business partner, formed a charter airline company in the late 1970s and flourished under Noriega's patronage. Carlton said he often served as Noriega's personal pilot, flying him around Panama.

"People would see us with him, and they wouldn't bother us, they wouldn't check our luggage," he said. "We would receive fuel, parts, anything we wanted at the airport without paying."

At first, with Noriega's approval, Carlton and Rodriguez were flying arms to leftist guerrillas in El Salvador, Carlton said. But that ended when one of Rodriguez's planes crashed in mid-June 1980. Then in September 1982, Carlton testified, he was invited to Medellin where Escobar and Gaviria asked him to fly cocaine. But when Carlton relayed the proposal to Noriega, he said, Noriega "became exceedingly upset" and threatened to jail him.

About two weeks later, however, Carlton said Noriega directed him to "go ahead and talk to those people." But when he reported back that Escobar and Gaviria were offering him between $30,000 and $50,000 for the first flight, Noriega again became angry, Carlton said.

Noriega "told me, he didn't know whether they were crazy or I was crazy," Carlton said. "He would not allow that to happen for less than $100,000."

Escobar agreed, and Carlton began flying from Medellin to Panama, he said. The first flight, he later learned, was a practice run with no drugs. Aboard the next three flights, he said, were between 880 and 1,100 pounds of cocaine at $160,000 per flight.

In negotiations on the fourth flight, Noriega told him that he was "a fool" for receiving so little, Carlton said. "You know how much they're selling a kilogram for in Miami?," Carlton said Noriega asked him. "He told me to take advantage because this was going to be the last flight."