Culminating a year-long investigation, federal agents and local law enforcement officers yesterday arrested dozens of people in 14 cities across the country in a crackdown against what FBI officials described as a major drug distribution network.

By late afternoon, the FBI said that 77 arrests had been made in an operation dubbed "Southwest Express" and that more than 20 additional arrests were expected. Those who were arrested were charged with drug trafficking, money laundering and conspiracy.

The raids were targeted on an organization headed by Omar Rocha Soto of San Diego. Rocha and his wife, Adriana Espinoza, were arrested early yesterday morning as they left their home in a San Diego suburb, FBI officials said.

Law enforcement authorities also arrested in El Paso yesterday three brothers involved in the operation--Daniel, Raul and Angel Sotello-Lopez. The brothers played a key role in coordinating the transportation of illegal drugs from the Southwest to Chicago, where the drugs were later shipped to cities in the East and South, officials said.

"This makes what we feel is a significant dent," said Thomas Pickard, assistant director of the FBI's criminal investigative division. "We think this is one of the major drug trafficking organizations here in the United States."

Pickard said that over the course of the investigation, law enforcement authorities seized 2,727 kilograms of cocaine, 4,158 pounds of marijuana and more than $1.1 million in cash. Yesterday's raids resulted in the seizure of 14 kilograms of cocaine, two Ferrari automobiles, a Land Rover and seven weapons, including an AK-47 assault rifle, he said.

According to Pickard, the drugs distributed by the Rocha organization originated in a number of countries in Central and South America and Southeast Asia and were smuggled into the United States through San Diego and El Paso. From there, he said, the organization shipped the drugs to Chicago in hidden compartments in automobiles, tractor-trailers and rail cars.

From Chicago, associates of the organization sent the drugs to Cleveland, New York and Boston, and from those cities, some of the drugs were moved to Nashville and Atlanta, Pickard said.

Pickard described the Rocha organization as one of the "top 20" drug distribution operations in the country. He said Rocha was "loosely associated" with a number of organizations that supply the illegal drug market. "But he was in it for the profit purely; and whatever organization would give him the best deal on the dollar, Mr. Rocha was there," Pickard said.

"This organization that we disrupted today embraced the American capitalist idea and would sell any type of drug for a profit and did not discriminate in its dealings with any other drug organizations," he added. "For example, they sold to Dominicans, blacks, Middle Easterners and any other organized crime group throughout the United States."

"He was definitely on his way to being a big, big-time trafficker," Errol Chavez, chief of the Drug Enforcement Administration's San Diego office, told the Associated Press.

Pickard said federal authorities were less concerned with the amount of drugs they seized in the investigation than with disrupting the distribution organization. "We were trying to disrupt the organization, the leadership and the infrastructure. We weren't trying to count how much drugs we seized or put on the table," he said. "Our emphasis here was on the leadership--Omar Rocha and the Sotello brothers. We wanted to get them off the street by taking out the hierarchy of this drug organization."

Officials said the investigation was conducted jointly by the FBI, the DEA, the Justice Department, the U.S. Customs Service, the Internal Revenue Service, the Immigration and Naturalization Service and more than 50 state and local law enforcement agencies. Yesterday's arrests and searches of more than 70 sites took place in San Diego; El Paso; Houston; Lufkin, Tex.; Chicago; La Salle, Ill.; Cleveland; Dayton, Ohio; Allentown, Pa.; New York; Albany, N.Y.; Boston; Nashville; and Atlanta.

CAPTION: Joseph Keefe, left, and Thomas Pickard of the FBI appear at a news conference with Donald Shurhan of U.S. Customs.