* European rights court says Britain can extradite Islamist cleric
* Britain's most notorious cleric to face trial in United States
* Hook-handed cleric had hailed Sept. 11 attacks
* Hamza argued his rights would be contravened in U.S. (Adds background)
By Gilbert Reilhac
STRASBOURG, France, April 10 (Reuters) - Britain can extradite its most notorious Islamist cleric to the United States to stand trial on charges that he supported al Qaeda and aided a fatal kidnapping in Yemen, the European Court of Human Rights ruled on Tuesday.
Egyptian-born Abu Hamza al-Masri, a one-eyed radical with a metal hook for a hand who praised the Sept. 11, 2001 attacks, faces a sentence of over 100 years in high-security U.S. prisons if found guilty, a step he said would contravene his human rights.
But the seven judges at the Strasbourg-based European Court of Human Rights ruled unanimously that sending Hamza and four other suspects to such "Supermax" penitentiaries would be lawful and that they would not receive "inhuman and degrading treatment".
The court gave the suspects - including Babar Ahmad, Syed Tahla Ahsan, Adel Abdul Bary and Khaled Al-Fawwaz - three months to appeal against the ruling to a panel of five European judges.
The case, pitting the rights of men suspected of grave crimes against the demands of the United States for justice, has electrified the British media, which vilified Hamza as "the hook-handed hate preacher" and agitated against hindrances to his extradition.
"Sling your hook," a frontpage headline in Britain's best selling newspaper, The Sun, once read, next to a picture of the preacher.
The Strasbourg court said U.S. authorities would however not allow Hamza, who sports a metal hook after losing his hands in unclear circumstances in Afghanistan, to serve his sentence in the Florence Administrative Maximum Facility (ADX) prison in Colorado because of his disabilities.
Usually known for needling governments over human rights breaches, the court ruled that incarceration in Florence ADX - known as the "Alcatraz of the Rockies" and home to gang leaders, serial killers and bombers - for the other suspects would not amount to ill-treatment.
Some of world's most notorious convicts, including Sept. 11 plotter Zacarias Moussaoui, al Qaeda "Shoebomber" Richard Reid and Theodore Kaczynski, known as the "Unabomber", have been sent to the prison.
The prison currently houses 437 of the U.S. Federal Bureau of Prisons' "most violent, disruptive, and escape-prone inmates". Prisoners are housed alone in their cells, where the bed, desk, and stool are concrete and the showers, toilets, and sinks are stainless steel, according to the bureau.
MENTAL HEALTH REPORT
The European court adjourned its ruling on a sixth suspect, Haroon Rashid Aswat, pending a mental health report.
A former preacher at the Finsbury Park Mosque in north London, Hamza is viewed as one of the most radical Islamists in Britain, a country he has attacked for its support of U.S.-led wars in Iraq and Afghanistan.
At the red-brick mosque, dozens of worshippers streaming in for prayers were reluctant to talk about Hamza.
"People who are not Muslims think anyone who came into the mosque were extremists," Youba Sidali, a 30-year-old from Algeria, told Reuters below the white minaret. "I think Abu Hamza doesn't represent Muslims."
Hamza was jailed for seven years in 2006 for inciting murder and racial hatred and for possessing literature such as the Al Qaeda Handbook, a manual on how to wage war against governments and replace them with Muslim ones.
Hamza - real name Mustafa Kamal Mustafa - was indicted by a federal grand jury in new York in April 2004. He was accused of involvement in a 1998 hostage taking in Yemen which resulted in the deaths of four hostages - three Britons and one Australian.
He was also accused of providing material support to al Qaeda by trying to set up a training camp for fighters in the Pacific state of Oregon and of trying to organise support for the Taliban in Afghanistan.
The U.S. Justice department welcomed the European court's decision in the cases of Hamza and the other four suspects.
"We look forward to the court's decision becoming final and to the extradition of these defendants to stand trial in the United States," spokesman Dean Boyd said. "With respect to defendant Haroon Rashid Aswat, U.S. officials will consult with the United Kingdom's Home Office about the additional submission requested."
British Prime Minister David Cameron, who visited President Barack Obama in Washington last month, said he was pleased with the decision but frustrated with the time it took to approve the extradition.
"I'm very pleased with this news," Cameron said. "It's quite right that we have a proper legal process although sometimes you can be frustrated by how long this takes."
To the fury of many members of Cameron's Conservative party, Britain was forced to free another radical cleric, Abu Qatada, from prison in February to live under virtual house arrest after the European Court of Human Rights ruled his detention without trial was unlawful. (Writing by Guy Faulconbridge and Peter Griffiths; Additional reporting by Yeganeh Torbati in London and Jeremy Pelofsky in Washington; Editing by Giles Elgood)