Considered a leader of ETA’s hard-line wing, Aspiazu, known as ‘Txeroki’, was arrested in a predawn raid on a rented apartment in the French Pyrenees spa resort of Cauterets in November 2008.

He was transferred to Spain in May of this year on a temporary basis to face trial.

The National Court convicted him of 20 counts of attempted terrorist murder and one of causing damage, the ruling said.

In one case cited in the ruling, he was involved in an attempted assassination in a bomb attack of the deputy mayor of the northern town of Portugalete, Esther Cabezudo.

He was also ordered to pay 155,800 euros ($223,400) to Cabezudo, almost 400,000 euros to other victims and close to one million euros for material damage.

Despite the 377-year sentence, prison terms are limited to 40 years in Spain for terrorist crimes.

Aspiazu was acquitted last June over the attempted assassination of the head of the Basque media group Correo, Enrique Ybarra, in 2002.

Police also suspect he was involved in a bomb attack at the car park at Madrid airport in December 2006 that killed two Ecuadorian immigrants.

The bombing torpedoed tentative peace talks between ETA and the Socialist government of Prime Minister Jose Luis Rodriguez Zapatero.

A judge in Paris charged him in connection with the December 2007 killing of two undercover Spanish police officers in southwestern France.

Meanwhile, Spain’s National Court acquitted a former Basque separatist leader who was sentenced to two years in prison for defending terrorism.

Arnaldo Otegi, one-time leader of the outlawed Batasuna party, linked to the armed group ETA, was convicted in 2010 for defending terrorism while paying homage in 2005 to an imprisoned ETA member. But the Supreme Court ordered a retrial saying one of the judges had made impartial comments.

The National Court said Friday it had acquitted Otegi for lack of evidence.

Otegi is in jail on provisional charges of trying to reform Batasuna. He has several cases pending.

ETA has killed more than 825 people since the late 1960s in its campaign for an independent Basque state. It declared a cease-fire last year.

On Jan. 10, ETA announced a permanent, verifiable cease-fire. But Spain’s government rejected the offer, demanding the group go further and disband entirely.