By Tabassum Zakaria

WASHINGTON (Reuters) - The CIA had information about three of the Sept. 11 hijackers at least 20 months before the attacks occurred but failed to pass the information on to other agencies, a congressional investigator said on Friday.

The CIA and FBI had no information linking 16 of the 19 hijackers to terrorism or terrorist groups before the Sept. 11, 2001, attacks on America and they may have been picked for that reason, Eleanor Hill, staff director of the joint inquiry into Sept. 11 attacks, said in testimony at a hearing of the House of Representatives and Senate intelligence committees.

The other three hijackers, all of whom were on the plane that crashed into the Pentagon, did come to the attention of intelligence agencies before Sept. 11. They were Saudi citizens Khalid al-Mihdhar, Nawaf al-Hazmi and his brother Salim al-Hazmi.

Four hijacked planes crashed into the World Trade Center in New York, the Pentagon near Washington and a Pennsylvania field, killing about 3,000 people. The United States has blamed Osama bin Laden and his al Qaeda network.

Al-Mihdhar and Nawaf al-Hazmi attended a meeting of suspected associates of bin Laden's network in Kuala Lumpur, Malaysia from Jan. 5 to 8, 2000, she said.

Also at that meeting was Khallad bin-Atash, "a key operative in Osama bin Laden's terrorist network," and it was held at a condominium owned by Yazid Sufaat who in October 2000 signed letters identifying Zacarias Moussaoui as a representative of his company, Hill said.

Moussaoui is the only person charged in the United States in connection with the Sept. 11 attacks.

"Although it was not known what was discussed at the Malaysia meeting, the CIA believed it to be a gathering of al Qaeda associates," Hill said. Al-Mihdhar and al-Hazmi then went to another Southeast Asian country, she said.

CIA DID NOT KNOW WHAT NSA KNEW

By the time the suspected hijackers entered Malaysia, the CIA knew al-Mihdhar's name, passport number, and birth information, and that he had a U.S. multiple-entry visa issued in Jeddah, Saudi Arabia, that expired on April 6, 2000, Hill said.

The CIA did not know that the National Security Agency, which eavesdrops on global communications, had information associating Nawaf al-Hazmi with bin Laden's network because the NSA did not immediately disseminate it, she said.

One of the main criticisms of the intelligence agencies has been that they did not adequately share information within their agencies or with each other.

The names of al-Mihdhar and Nawaf al-Hazmi could have been added to the State Department, Immigration and Naturalization Service, and U.S. Customs watch lists, denying them entry into the United States, but they were not, Hill said.

A CIA communication in early January 2000 said al-Mihdhar's travel documents including his multiple-entry visa for the United States were shared with the FBI for investigation, but no one at the FBI recalls receiving them, she said.

The CIA continued to be interested in al-Mihdhar and al-Hazmi after they left Malaysia with help from foreign authorities.

In March 2000, CIA headquarters received information from an overseas CIA station that Nawaf al-Hazmi had entered the United States through Los Angeles International Airport on Jan. 15, 2000.

"The CIA did not act on this information," Hill said. Nor did it consider the possibility that because Nawaf al-Hazmi and al-Mihdhar had been together in Malaysia there was a probability they would travel further together. Al-Mihdhar traveled with al-Hazmi to the United States on Jan. 15, 2000, she said.

Although the two had already entered the United States, sharing the information with the FBI and other agencies could have prompted an investigation to find them and keep their activities in the United States under watch, Hill said.

"Unfortunately, none of these things happened," she said. "The failure to watchlist al-Mihdhar and al-Hazmi or, at a minimum, to advise the FBI of their travel to the United States, is perhaps even more puzzling because it occurred shortly after the peak of intelligence community alertness to possible millennium-related terrorist attacks," Hill said.