The sister of France's first lady Carla Bruni-Sarkozy said today she played a part in President Nicolas Sarkozy's decision not to extradite a former Red Brigades member to Italy as ordered by the courts.

Rome has long demanded the extradition from France of several former activists from the violent far-left group, including convicted murderer Marina Petrella, and Sarkozy's U-turn is likely to anger the Italian government.

She was found guilty in absentia by an Italian court in 1992 of murder, kidnapping, attempted kidnapping and armed robbery.

Petrella, who has lived in France for more than two decades, was arrested in August last year at Italy's request, shortly after Sarkozy came to power promising to end France's policy of giving asylum to repentant ex-members of the Red Brigades.

A French court approved her extradition in December and an order to send her back to Italy had been signed by the prime minister.

However, Sarkozy's office announced at the weekend that he had decided to reverse the extradition order on humanitarian grounds and the president's Italian-born sister-in-law, Valeria Bruni-Tedeschi, said she had intervened on Petrella's behalf.

"I told him (Sarkozy) about her, especially just after I saw her in jail. I gave him some information that was perhaps a little bit important in his decision," Bruni-Tedeschi, an actress, told French radio station Europe 1.

"He focused his attention on a case that he hadn't completely focused on before," said Carla's elder sister.

The French newspaper Liberation reported on Monday that Carla and Valeria visited Petrella last Wednesday to assure her she would not be extradited.

Since her arrest, Petrella, who was born in 1954 has fallen into a severe depression, lost the will to live and wasted away to a weight of about 40 kg (88 pounds), according to her supporters who include Bruni-Tedeschi.

The Red Brigades carried out a campaign of violence in Italy during the "years of lead" in the 1970s, culminating in the kidnap and murder of former Prime Minister Aldo Moro in 1978.

The Bruni sisters were born in Italy to a rich family of entrepreneurs who emigrated to France partly because they feared kidnappings for ransom during the so-called "years of lead".

It is not immediately clear why Valeria or Carla took up Petrella's cause.