A veteran Cuban exile militant linked to a string of violent acts against Fidel Castro and his government is reportedly in South Florida seeking safe haven.

BY ELAINE DE VALLE AND ALFONSO CHARDY

Luis Posada Carriles, the legendary Cuban exile operative accused of blowing up a Cuban airliner in 1976 and trying to kill Fidel Castro in 2000, is believed to have secretly slipped into South Florida after years of hiding abroad, a federal source said Wednesday.

The source said he understands that Posada, 77, has been in the area for about a week and has made contact with government authorities.

The source said he may be trying to retain a local attorney, but didn't explain why. One possibility might be to help ensure Posada wouldn't be extradited to Venezuela, where he escaped from prison in 1985 while facing charges related to the airliner bombing.

The Cuban-born militant, however, does not face any charges in the United States.

Santiago Alvarez, a Miami developer who is a close friend and financial backer of Posada, said he talked to three attorneys on Wednesday in case his friend decides to come forward and seek asylum. Alvarez, however, said he would neither confirm nor deny Posada is in the area.

''I cannot tell you if I have seen him or have not seen him, if he is here or is not here,'' Alvarez said. ``What I can tell you is that I am signing a contract with a lawyer to represent him in case it is true that he is here and that he will present himself to immigration.''

Were Posada to emerge publicly in Miami, his presence could pose an embarrassing foreign-relations dilemma for the Bush administration. Amid the U.S. war on global terrorism, Posada's alleged involvement in hotel bombings and assassination plots could leave the nation open to criticism, especially by Cuba and Venezuela, whose governments are antagonistic toward American policies.

AGREEMENT CITED

In Washington, Venezuelan Ambassador Bernardo Alvarez Herrera stopped short of saying his country would seek the extradition of Posada.

''If the presence of this person on U.S. soil is confirmed, the Venezuelan government has a cooperation agreement [with the United States] regarding judicial matters and there is also an extradition treaty,'' Alvarez said.

''We have already asked for extradition of this person [from Panama in 2001],'' he added. ''He is a person who has a judicial proceeding pending in Venezuela,'' where Posada and others allegedly hatched the plot to bomb a Cubana airliner off the coast of Barbados.

Though virtually any Cuban who reaches U.S. soil would be entitled to stay under current immigration policy, Posada is no ordinary Cuban refugee.

He is a highly controversial figure who was a Bay of Pigs veteran with ties to the CIA dating back to the 1960s. An icon to some in the exile community, Posada has been linked to assassination and sabotage operations against Castro and his government, including a string of bombings against Havana tourist spots in 1997.

A federal official said Posada's name has been on an immigration watch list for years in case he should try to enter the country through an airport, seaport or border crossing.

But Santiago Alvarez, the longtime friend and benefactor, said that if Posada were here he would likely have sneaked across the border.

''He has family -- a son, a daughter and a wife -- here [in Miami],'' Alvarez said. ``If he wants to come to immigration, we are ready to represent his case. Whenever he decides what he wants to do, we'll help him.''

Alvarez said Posada, who once was a permanent resident in the United States, gave up that status years ago when he moved to Latin America to pursue anti-Castro operations.

He worked for the Venezuelan secret police for several years. Then, in 1976, he and Miami pediatrician Orlando Bosch were arrested following the midair bombing of a Cubana airliner that killed all 73 people aboard.

Both were acquitted twice at trial, but were not immediately released pending an appeal by prosecutors. Bosch served 11 years behind bars and was released.

ESCAPE FROM PRISON

But in 1985, Posada escaped from prison. He turned up a year later in El Salvador, where he worked for an unauthorized Nicaraguan contra resupply network overseen by then-National Security Council staffer Oliver North.

In 1997, he first admitted and then denied masterminding the bombing attacks on several Havana hotels and restaurants that catered to foreign tourists, who provided needed currency to cash-strapped Cuba.

Three years later, Posada and three Miami exiles were arrested in Panama after Castro, visiting for a heads-of-state summit, alleged at a news conference that they were plotting to kill him. The four claimed they were trying to help a Cuban general defect.

They were cleared of the assassination and explosives charges, but were convicted of endangering the public safety and given sentences of up to eight years in prison.

Last year, then-Panamanian President Mireya Moscoso issued a controversial pardon to the four, prompting Cuba to break off diplomatic relations with Panama. The three Miamians returned home, but Posada remained in Central America.

He was last seen publicly in August in Honduras. The Cuban government formally requested his capture and extradition -- to face a firing squad. But Posada managed to disappear again.

The first hint Posada might be in the Miami area came Tuesday night, when Spanish-language television station Channel 41 quoted three unidentified sources as saying he was here and planning ``to present himself to North American authorities.''

On Wednesday, El Nuevo Herald, also citing unidentified sources, reported Posada was in Miami ''to negotiate his surrender'' to U.S. authorities.

FBI STATEMENT

Judy Orihuela, spokeswoman for the FBI, said Posada has not contacted the agency. Carlos B. Castillo, spokesman for the U.S. Attorney's Office in Miami, said prosecutors also have not heard from Posada.

A Department of Homeland Security official, who spoke on the condition of anonymity, said only that the agency is ``working closely with our law enforcement partners and we're looking into the matter.''

Herald staff writers Nancy San Martin and Jack Dolan contributed to this report.