Cuba has denounced as a "farce" the acquittal in the United States of Luis Posada Carriles, a former CIA agent who is accused of terrorist attacks against the island.

The foreign ministry said Friday's verdict, which found the 83-year-old not guilty on all 11 counts of perjury, obstruction of justice and immigration fraud, showed the US continued to protect a known terrorist.

"This is an additional demonstration of the support and shelter the American authorities have historically given him," it said in a statement over the weekend.

A jury in El Paso, Texas cleared Posada Carriles after deliberating for just three hours, an unexpectedly swift climax to a closely watched 13-week trial which cast fresh light on the octogenarian's lengthy career as an anti-communist agent. The defendant, a hero to militant anti-Castro exiles, hugged his lawyers and told reporters he was grateful to the US, the court and the jury for what he said was a fair trial.

"What happened here should serve as an example for justice in my country, Cuba, which is unfortunately in the hands of a dictator."

Posada Carriles, who as a student came into contact with a young Fidel Castro, opposed the revolutionary government which seized power in 1959 and three years later joined a CIA-backed invasion by Cuban exiles.

The attack flopped but he escaped, was trained in sabotage by US handlers and spent the next decades plotting to kill Castro and other leftwing targets in the region.

He moved to Venezuela where he was accused of masterminding the 1976 suitcase bombing of a Cubana Airlines jet that killed 73 people, including the national fencing team. Months earlier his links with the CIA were severed, according to declassified US documents.

Posada Carriles escaped from a Venezuelan jail in 1985, where he spent eight years awaiting trial for the atrocity, which he denied, and resumed plotting against Castro. In an interview with the New York Times he took responsibility for 1997 bomb attacks against Cuba's tourist industry, which killed an Italian tourist in a Havana hotel, but later recanted the confession.

He was arrested in possession of explosives in Panama in 2000 and charged with plotting to assassinate Castro at a regional summit. He served four years in jail before being pardoned by Panama's outgoing president, Mireya Moscoso, prompting accusations of political cronyism between Panama, Cuban exiles in Miami and the Bush administration.

In 2005 Posada Carriles surfaced in Miami. The US refused Cuban and Venezuelan extradition requests, claiming he would not receive a fair trial in either country. Caracas and Havana accused the US of hypocrisy in allowing the region's most notorious terrorist to live freely and openly while amid the post 9/11 "war on terror".

Soon afterwards US authorities charged Posada Carriles with the relatively minor offences of lying to immigration officials about how he entered the US and his role in the Havana bombings. More than 20 prosecution witnesses testified in the court.

Jurors heard him speaking English in recordings by Ann Bardach, the New York Times journalist to whom he spoke about the bombings, despite later claiming he did not speak the language.

Observers expected convictions on at least some of the charges but the jury stunned prosecutors with a swift, unanimous and complete acquittal.

"We're obviously disappointed by the decision," said a justice department spokesman, Dean Boyd.

The head of Cuba's parliament, Ricardo Alarcon, accused the judge, Kathleen Cardone, of not allowing jurors to see crucial evidence.

"The stupid and shameful farce is over," he told AP. "There were things the jury did not know."

Venezuela's government denounced the trial and verdict as "theatre" and said Washington continued to shelter a mass murderer.

"The US government's protection of Posada Carriles has become an emblematic case of the US double standard in the international fight against terrorism," the foreign ministry said in a statement.

Posada Carriles's lawyer said he planned to return to his home and family in Miami. Leaders of Miami's Cuban exile community said he should be left to live in peace and that it was time to look ahead, not backwards.