Over 600 people turned up at the prison near the southern French city of Montpellier to greet Bove, who had received a three-month sentence for the 1999 anti-U.S. protest.

Bove was released early thanks to sentence reductions for good conduct, a recent presidential pardon for minor offenders and time he had already served in custody before sentencing.

Dressed in a white T-shirt and faded jeans, the head of the radical Confederation Paysanne farmers' union thanked the crowd for its support, which he said "turned this intolerable sentence into a resistance movement".

"Our struggle is just starting. We must denounce the arbitrary actions of the government of (Prime Minister Jean-Pierre) Raffarin that puts trade union leaders into jail.

"Prison is abominable, but I was here for all of you, so that helped me," said Bove, whose supporters camped outside the prison to keep a 24-hour solidarity vigil during his stay there.

"AN AWKWARD CUSTOMER"

Bove hit the headlines in August 1999 by leading anti-globalisation activists in an attack on a McDonald's hamburger restaurant under construction in the southern town of Millau.

He was particularly upset by duties Washington had imposed on such classic French specialities as Roquefort cheese and foie gras to retaliate against the European Union's refusal to lift a ban on importing hormone-treated beef from the United States.

"We had no other way to denounce this scandal," he said. "The World Trade Organisation had just ordered Europe to accept hormone-treated beef. It was illegal, but when legality is illegitimate, it's legitimate to move into illegality."

The media-savvy Bove, who turned his entry into prison on June 19 into a mass protest by tractor-driving colleagues, later joined supporters in a huge picnic near the prison and a public discussion about genetically modified food.

With his trademark walrus moustache, impish style and fluent English learned during his childhood in California, Bove has become a regular at anti-globalisation jamborees such as protests against the World Trade Organisation.

He has also led his supporters several times in destroying fields of genetically modified maize and other crops and may have to return behind bars on charges in those cases.

"Prison still awaits Jose if the appeals court does not throw out another sentence of 14 months he has, and he still faces another trial on September 17," his lawyer Francois Roux said.

Bove staged a hunger strike for almost a month in jail, losing 11 kilos drinking only water and one glass of orange juice a day. He was reportedly the centre of attention in the jail and talked frequently with other prisoners.

Bove called his time in jail an unbearable experience unfit for any human being and attacked plans by the new centre-right government to lower the minimum age for imprisonment to as young as 13 in some cases.

"It is not worthy of a country that calls itself the home of human rights," he said of prison conditions. "Whatever they've done, the prisoners don't deserve that."

"He's an awkward customer for the jail services," Justice Minister Dominique Perben remarked this week. "He's served his sentence and he's getting out. I hope he has fewer problems with the justice system in future."