WASHINGTON, Dec. 30 — Representatives of Osama bin Laden contacted Iranian intelligence agents in the mid-1990's in an attempt to forge an anti-American alliance of terror between Iran and Mr. bin Laden's network, Al Qaeda, according to United States intelligence reports.

In 1996 a close ally of Mr. bin Laden sought out Iranian intelligence officers in Afghanistan to see if they would join forces with Mr. bin Laden to strike American targets, the secret intelligence reports say.

That contact followed a visit to Iran in December 1995 by another bin Laden associate, according to the documents, which were obtained by The New York Times.

Iranian intelligence agents responded that they were willing to meet personally with Mr. bin Laden in Afghanistan, but it is unclear from the reports if such a meeting ever occurred, and if so, whether any agreement was reached.

The intelligence reports, which remain classified, provide some of the most concrete evidence ever disclosed of Mr. bin Laden's attempts to forge an alliance with a major Middle Eastern country just as he was starting his terror campaign against the United States.

Since the Sept. 11 attacks on the World Trade Center and the Pentagon, the debate in the United States over whether Mr. bin Laden has received state sponsorship has focused on inconclusive reports of contacts between Al Qaeda and the Iraqi government. But the secret intelligence reports show that Mr. bin Laden and his allies were eager to turn to Iran, which had a longer history of support for terrorist acts against the United States and Israel.

Iran, dominated by Shiite Muslims, has tended to support Shiite- based extremist groups like Hezbollah in Lebanon rather than Sunni Muslim extremists like Al Qaeda. Iran fiercely opposed the Taliban in Afghanistan, largely because the Taliban movement was dominated by Sunni fundamentalists.

The fact that the Taliban had given Mr. bin Laden sanctuary in Afghanistan only made any alliance between Tehran and Mr. bin Laden, a Saudi exile, even more unlikely.

But it appears that at least some Iranian intelligence officials believed that they could join with Mr. bin Laden's forces against their common enemy, the United States.

A United States official declined to comment on the specific intelligence reports detailing contacts between bin Laden representatives and Iranian intelligence. But the official said there was no evidence today of an alliance between Al Qaeda and Iran.

"In terms of the possibility of Al Qaeda operatives transiting Iran, or pitching up there overnight, that would not be surprising," the official said. "But the notion of a more formal, active cooperative arrangement between the two today, I would suggest they don't make very good bedfellows. There is no credible evidence that points in that direction of any alliance today."

The intelligence reports say that on July 31, 1996, Abdullah Nuri, said to be a leading member of a Islamic militant group in Tajikistan and a close ally of Mr. bin Laden, contacted agents from the Iranian Ministry of Intelligence and Security in the northern Afghan city of Taliqan, not far from the border with Tajikistan.

He asked for a meeting between Mr. bin Laden and an Iranian representative, an American intelligence report says. Mr. Nuri urged the Iranians to get in touch with Mr. bin Laden, who was said to be in Jalalabad, Afghanistan, at the time. In response, the Iranian intelligence officers made clear that they were willing to meet him but that he should go to Taliqan to see them.

Mr. Nuri replied that Mr. bin Laden was reluctant to travel to Taliqan, a part of Afghanistan where he might come under attack.

Mr. Nuri urged the Iranians to send a representative to meet Mr. bin Laden in Jalalabad instead. The reports do not show whether the Iranians ever did so.

The intelligence reports suggest that Mr. Nuri's efforts to bring Al Qaeda and Iranian agents together were not the first contacts. In December 1995, Mustafa Hamid, also known as Abu Walid, an Egyptian associated with Al Qaeda, visited Iran, according to an American intelligence report.

Mr. Nuri and Mr. Hamid apparently knew each other, because Mr. Nuri had introduced Mr. Hamid to an Iranian intelligence officer known as Rahmati in Taliqan, the intelligence report says.

At the time of the contacts between Al Qaeda and Iranian intelligence, Iran was deeply involved in terrorist activities against the United States, American officials say.

In June 1996, Islamic militants bombed the Khobar Towers complex in Dhahran, Saudi Arabia, killing 19 members of the American military, and United States officials have said they suspect that at least some Iranian officials were behind the bombing plot. Last June a federal grand jury charged 13 Saudis and a Lebanese in the bombing, and the indictment implicated Iranian officials, although none were identified or charged.

Despite a series of recent political victories by reformists in Iran led by President Mohammad Khatami, hard-line elements of the Iranian security apparatus are still believed to support terrorist activities, prompting the State Department to describe Iran in a recent report as "the most active state sponsor of terrorism in 2000."

United States officials say Mr. Khatami has little control over the security and intelligence officials who back terrorist groups.

But in recent years, Iranian security forces have focused their support for organizations that aim their attacks at Israel, rather than the United States, including Hezbollah in Lebanon and the Palestinian group Hamas. Khobar Towers appears to be the last major anti-American terrorist operation supported by Iran.

The Bush administration, like the Clinton administration before it, has been eager to improve relations with Iran and has not talked of it as a possible target in President Bush's new global campaign against terror.

While intelligence and security officials in Tehran have long had an interest in anti-American terrorism, by the mid-1990's the Iranians were also playing a delicate balancing act in Afghanistan, making it difficult for them to consider an alliance with a terrorist leader under the Taliban's protection. Mr. bin Laden moved from the Sudan to Afghanistan in 1996.

In fact, just as their intelligence officers were considering whether to meet with Mr. bin Laden, the Iranian government was moving to oppose the Taliban, which had just gained control in Kabul.

According to a United States intelligence report, on Sept. 28, 1996, Iran's National Security Council met and agreed to help create a northern front composed of Uzbeks, Tajiks and Shiites to counter the Taliban. The Iranian intelligence service and Iranian Revolutionary Guards were ordered to travel to Mazar-i-Sharif and Taliqan in northern Afghanistan to help forge the new opposition.

A month later, during another Iranian security council meeting, senior officials agreed to push for the early liberation of Herat in western Afghanistan to ensure greater freedom of movement of Iranian-backed opposition forces and their supplies from Iran, according to the American intelligence reports.

Later, the Revolutionary Guards, a militant cadre in the Iranian security apparatus, were given the main operational responsibility for Iran's involvement in Afghanistan, the intelligence reports said.

Eventually Iran joined forces with Russia in providing support for the Afghan opposition, and Iran's battle against the Taliban may have made it impossible for Mr. bin Laden to forge an alliance with Iranian intelligence. By June 1997 the Taliban had closed Iran's embassy in Kabul.