(Updates with details after arrival, quotes)

By James Mackenzie

PARIS, Dec 28 (Reuters) - Six French aid workers sentenced to eight years hard labour in Chad for trying to kidnap 103 children arrived on Friday in France where they are due to serve their sentences in jail.

France invoked a judicial cooperation treaty with its former colony to obtain the quick transfer home of the six, who were convicted of abduction by a Chadian criminal court on Wednesday.

The four men and two women from French humanitarian group Zoe's Ark arrived at Le Bourget airport near Paris and were interviewed by state prosecutor Francois Molins before being transferred to an unidentified prison.

They were weak and demoralised but otherwise in good health, he told reporters, adding: "They realise that they're facing a period that is going to be difficult."

A group of family members and supporters, some bearing signs with slogans like "They were only thinking of the children" was waiting at the airport but did not see any of the six, who were taken away out of sight of reporters or the public.

"We asked to see them. It was refused," Christine Peligat, wife of the group's logistics specialist Alain Peligat told Reuters. "I'm worried about the medical side."

Their departure from Chad followed a highly publicised legal case and diplomatic imbroglio which had embarrassed France, a key backer of Chadian President Idriss Deby. French troops and planes stationed in Chad have given logistical and intelligence support to Deby's army fighting rebels in the east.

France is also the main contributor of troops to a European Union peace force preparing to deploy in eastern Chad to protect thousands of Sudanese refugees and displaced Chadian civilians.

French President Nicolas Sarkozy, who is on holiday in Egypt and had personally lobbied for the six to be returned to France, spoke by telephone with Deby on Thursday, French officials said.

ANTI-FRENCH PROTESTS

The aid workers were arrested in October as they tried to fly the children, aged one to 10, from eastern Chad to Europe for fostering with families there.

The workers said they had been on a humanitarian mission to rescue orphans from Sudan's war-torn Darfur region, across Chad's eastern border.

But most of the 103 children were found to have come from families in Chadian border villages who were persuaded to give up the infants in return for promises of education.

The Zoe's Ark case sparked anti-French protests in the Chadian capital N'Djamena and in Abeche in the east.

Many Chadians were angry over what they saw as meddling by Sarkozy, who flew to Chad in early November to collect three French journalists and four Spanish flight attendants who were freed after being arrested along with the Zoe's Ark six.

Under pressure from Paris and Madrid, Chad also freed three remaining Spanish aircrew and a Belgian pilot who had been detained in the case.

Zoe's Ark was widely condemned in France but there was shock at the severity of the sentences handed out to a group generally considered naive and misguided but not malevolent.

Being flown to France means the convicted aid workers will be spared hard labour, a sentence no longer imposed in France.

But they may face law suits lodged by families who had offered to look after the children in Europe. Diplomats say some of them paid several thousand euros per child.

It is not clear what effect the repatriation will have on the 4.12 billion CFA franc ($9 million) in compensation that the Chadian court ordered the convicted aid workers to pay the children's families. (Additional reporting by Moumine Ngarmbassa in N'Djamena, Laure Bretton in Paris; Writing by Pascal Fletcher)

AlertNet news is provided by