LONDON (Reuters) - The United States and Britain on Thursday aired evidence said to link Osama bin Laden to the attacks of September 11, and won declarations of support from NATO allies and, crucially, Pakistan.

The British government's release to the public of a dossier against the Islamic guerrilla leader, and the passing by U.S. officials of more detailed evidence to some friendly governments this week, are key steps in preparing international opinion for military action in Afghanistan which could be only days away.

British Prime Minister Tony Blair told parliament that intelligence gathered by Britain and its allies proved bin Laden and his al Qaeda network had "planned and carried out the atrocities" -- the attacks on New York and Washington.

In a 21-page document, the British government said it had evidence linking bin Laden, and the Afghan Taliban regime harboring him, to the suicide plane attacks on New York and Washington which left nearly 6,000 people dead or missing.

The biggest manhunt in history has been made more complex by the lack of any admission of guilt by bin Laden for the string of atrocities of which he has been accused in recent years.

While other guerrilla groups often issue warnings of attacks or statements of self-justification, bin Laden has made only general calls and has referred to specific attacks with only enigmatically vague words of approval. He is reported to have denied responsibility for the September attacks.

But the 21-page document made available to journalists in London said that, of the 19 hijackers identified from the passenger lists of the four planes hijacked in America on September 11, at least three had been identified as associates of bin Laden with a track record in his camps and organization. 

PREVIOUS ATTACKS

One of the three has been identified as a key plotter in attacks on U.S. embassies in east Africa in 1998 which killed more than 200 people, and later on the U.S. warship Cole in Yemen, it said.

Bin Laden urged close associates to return to Afghanistan by September 10 because a major operation was planned, it said.

It listed similarities among the attacks in recent years blamed on bin Laden, such as the bombings of the U.S. African embassies, of U.S. soldiers in Saudi Arabia in 1995 and 1996 and of the Cole.

Bin Laden's operations employed suicide attackers; showed total disregard for casualties, including among Muslims; gave no warnings; and were coordinated and meticulously planned, the document said.

It said bin Laden and al-Qaeda had been able to carry out the attacks because Afghanistan's Taliban gave them impunity.

"The document does not contain the totality of the material known to the government, given the continuing and absolute need to protect intelligence sources," the British government said.

It was unclear how much of the evidence in the document had been gleaned from electronic surveillance, inside informants, foreign governments or other sources. The United States has launched a worldwide campaign since September 11 to pool intelligence held by different governments.

The government of Muslim Pakistan, which has close links with the Taliban in neighboring Afghanistan, said on Thursday that evidence shown it by U.S. investigators "certainly provides sufficient basis for indictment in a court of law." 

OTHER COUNTRIES SEE EVIDENCE

Pakistan played a major role in the rise to power of the Taliban and is the only state which recognizes the puritanical Islamic movement as Afghanistan's legitimate government.

Asked if Pakistan would share the evidence with the Taliban, a spokesman said: "We have not been asked to do so and will not do so." The Taliban's demands that it be shown the evidence against bin Laden have been dismissed by Washington as a stalling ploy.

U.S. officials said on Wednesday Washington's NATO allies, Russia and Pakistan had been given similar briefings on the case against bin Laden. Gulf states have also been shown evidence.

Different countries were given varying amounts of information, partly determined by how much intelligence they had shared with Washington, a U.S. spokesman said.

NATO allies agreed on Thursday to give the United States all military aid it had requested, after NATO chief George Robertson called the evidence against bin Laden "clear and compelling."

The allies acceded to U.S. requests for unlimited use of their airspace, access to ports, airfields and refueling facilities, NATO airborne early warning aircraft, extra security for U.S. forces in Europe, intelligence sharing and replacement of any troops that might be moved from the Balkans.

While the case against bin Laden appeared to have won political consent internationally, a German official familiar with the international investigation said the legal evidence was not yet watertight.

"If you present a case to court you have to have not only clues but have it in a forensic way," he said. "We have not established this kind of link. It would not hold up in front of a court now."