CARACAS, VENEZUELA -- Colombian drug traffickers are buying land, banks and businesses here, turning Venezuela into a center for drug running, money laundering and arms trafficking, according to Venezuelan, Colombian and international narcotics experts.

"Venezuela had the roads, ports and economic infrastructure to allow drug trafficking to spring up almost overnight," said one Interpol official who monitors Colombia and Venezuela. "I have never seen a country change so dramatically in so little time."

Sources said Colombian cartels have allied with Sicilian organized crime families -- which have moved to Venezuela and maintain close ties to European heroin trafficking organizations -- to expand business and buy political protection.

"There are indicators that the Colombian cocaine cartels, presumably mostly from Cali, and the Sicilians are making a common front," said a knowledgeable U.S. official.

Throughout the 1980s, Venezuela -- flush with oil money and one of South America's most stable democracies -- seemed to be insulated from drug running and the related violence that plagued its neighbor. But in recent months the situation has changed dramatically.

The hub of activity is the coastal city of Maracaibo and the largely unpatrolled Colombia-Venezuela border, which is now one of the most important corridors for shipping drugs to the United States and Europe and for bringing in weapons to guerrilla and terrorist groups in South America, the officials said.

Earlier this month Colombian Defense Minister Rafael Pardo and his Venezuelan counterpart, Gen. Fernando Ochoa, agreed to form a joint task force to crack down on the border area. The U.S. Drug Enforcement Administration will open an office in Maracaibo in January.

"Our political and banking systems are completely penetrated and working with narco-traffickers," said Luis Hernandez, a congressman who was president of the legislature's Permanent Commission Against the Illicit Use of Drugs. "It is an exceptionally efficient organization."

A year ago, U.S. officials estimated annual cocaine exports through Venezuela at 82 to 88 tons. Today, Venezuelan and U.S. officials say the total is between 175 and 220 tons, or about a quarter of the cocaine sent to the United States and Europe.

"I have never seen so much stuff moving out as here," said one international narcotics official. "It is almost like Panama in the old days."

Exploiting centuries-old smuggling routes, the traffickers, dubbed the "Border Rat cartel" by law enforcement officials, move drugs across the Colombian border to ships on the Venezuela coast, and bring weapons back.

Among the groups making drugs-for-arms deals along the border are Peru's Maoist Shining Path guerrillas, Colombian Marxist insurgents and drug dealers from Peru, Colombia and Bolivia, law enforcement officials said. Among the leading dealers, according to U.S. and Venezuelan authorities, is the Makarem group, a shadowy clan of Lebanese Druze Christians based in Maracaibo who have obtained Venezuelan citizenship.

A November report by Venezuelan intelligence obtained by The Washington Post said many of the weapons from Europe are shipped through Suriname by the Makarem organization. Others arrive in small lots on shipping boats from Central America, where decades of civil strife are winding down and arms are cheap and abundant, according to a law enforcement official specializing in weapons sales.

Two incidents this month show how dangerous the trafficking has become.

On Dec. 3, the DEA announced the seizure in Miami of 12 tons of cocaine from the Cali cartel, shipped from Venezuela. It was the second-largest cocaine capture from a single place in the history of U.S. narcotics enforcement efforts. A related seizure had been made a few days before in Texas.

In what law enforcement officials now say is an associated development, Colombian authorities on Dec. 4 discovered graves containing 17 bodies outside Cucuta, a Colombian border town. The bodies, many showing signs of torture before gunshot executions, had been buried about a week when they were discovered.

"We are firmly convinced that narco-trafficking is behind this," said Col. Guillermo Ramirez, the Cucuta police commander. Other law enforcement officials said there was evidence that after the arrests were made in Texas, cartel hit men eliminated those suspected of giving information leading to the raid.

Officials said traffickers have amassed tens of thousands of acres along the border. There also has been a boom in exchange houses, hotels and banks in the area, a favorite way to launder money.

U.S. and Venezuelan officials confirmed that they are investigating one money exchange house near the Venezuelan border town of San Cristobal because it moved some $1 billion in the past year.

"They buy everything that is for sale, and many things that are not," said one U.S. narcotics official. "If they want something, they offer two or three times the going price, and offer to pay cash. If you refuse, they come back in a week or two with pictures of your family, and make threats, and if you still don't sell, they kill you. It is a vicious organization."

The alliance between Sicilian families in Venezuela and the Colombian cartels gives the cartels access to new routes to Europe and Canada, and help in laundering millions of dollars through Venezuelan banks and businesses. In return, the Sicilian families ship heroin to the United States through the cocaine pipeline, profit from Colombia's infant heroin industry and put cocaine into European supply lines.

Pasquale Cuntrera, a member of one of the implicated families, was indicted in Florida in 1990 for conspiracy to sell heroin. He and his brother Paolo are wanted by Italian authorities for heroin trafficking. However, because they, like other family members, have acquired Venezuelan citizenship, they cannot be extradited to stand trial, and move freely around the country.

Venezuela signed an information-sharing agreement with the United States earlier this year, but money laundering still is legal here.

In a television interview last month, Enrique Rivas Gomez, director of the cabinet-level National Commission Against the Illicit Use of Drugs, said the lack of financial laws makes Venezuela very attractive to traffickers and that the greatest problems are in the border states of Zulia, Tachira and Barinas. He warned that the Venezuelan economy was being "destabilized" by the huge influx of narco-dollars.

Law enforcement officials here said millions of dollars are laundered by "smurfing," in which money from drug sales in the United States is broken down into amounts less than $10,000 to avoid federal reporting requirements.

The money is given to "smurfs," or low-level members of the trafficking organization, who buy thousands of traveler's checks or money orders, which are then deposited into dozens of bank accounts. Once the funds are dispersed, or "smurfed," they are moved to other accounts to make it appear that they derive from legitimate business operations. The money then is transferred to traffickers in Colombia or Venezuela by smuggling out money orders and traveler's checks, or by wire transfers.

A U.S. District Court in New York has frozen 123 accounts suspected of being used to "smurf" millions of dollars for Colombian and Venezuelan traffickers.

According to court documents, "approximately 28 account holders have addresses in Caracas, Venezuela. Many of these primary account holders, who have a total of 15 primary accounts, share one post office box in Caracas. Six account holders share a different post office box in Caracas."