One of two trials for Josu Ternera, the former leader of Basque separatist group ETA, was postponed in Paris on Monday to next year after witnesses did not show up in court.

The first of two retrials for Ternera, arrested in France last year after years on the run, was to have been held on Monday and Tuesday before the Paris appeals court.

Ternera, whose real name is Jose Antonio Urrutikoetxea Bengoetxea, headed the ETA from 1977 to 1992 and is thought to have been behind a strategy of combining car bomb and shooting attacks in Spain in the 1980s.

In hiding since 2002, Ternera was convicted in absentia in 2010 on charges of associating with terrorists after his fingerprints were found in an apartment known to be used by ETA operatives in Lourdes, southern France.

He was sentenced to seven years in prison, and given a new eight-year term in 2017 after again being convicted in absentia of participating in a terrorist organisation.

After eluding police for years, he was arrested in May 2019 at a hospital in the French Alps where he was to undergo an operation.

As both prison sentences were handed down in his absence, he was able to request a retrial for both.

The first, now moved to February 22 and 23 next year, is on charges of having participated in the ETA between 2002 and 2005.

In the second matter, Ternera is scheduled to appear on Wednesday and Thursday before another Paris court over his alleged role in ETA's political apparatus between 2010 and 2013.

Ternera, who is 69 and has health problems, has been under house arrest in Paris with an electronic bracelet since July.

His extradition to Spain was approved in September 2019 to stand trial over a 1987 attack on a police barracks in the northern Spanish city of Zaragoza that killed 11 people, but an appeal is pending.

Another decision is due on November 18 on a second extradition request, concerning suspicion of Ternera's involvement in the 1980 murder of a director of French tyre company Michelin in Spain.