The FBI has arrested a Kuwaiti liquor store clerk who, authorities believe, engaged in numerous financial transactions with two of the hijackers in the World Trade Center attacks and has links to a suspected associate of Saudi militant Osama bin Laden.

The arrest of Nabil Almarabh, 34, came as the FBI raced to locate potential accomplices of the hijackers and to question people across the country who may have come in contact with them.

Federal investigators had spent days searching for Almarabh, who was wanted in Boston for a probation violation in connection with a stabbing there in May 2000. With guns drawn, FBI agents took him into custody late Wednesday night at a liquor store in the Chicago suburb of Burbank, Ill., where he was working as a clerk.

Now, investigators are trying to determine whether there is anything sinister about his having secured a Michigan license to haul hazardous materials such as dynamite, gases and toxic and radioactive waste.

Almarabh, who used to drive a cab in Boston, was a close friend of another former Boston taxi driver who has been identified by U.S. and Jordanian authorities as a bin Laden operative. That man, Raed Hijazi, has been convicted in Jordan of participating in an aborted plot to blow up ritzy hotels and Jordanian tourist sites where Americans and Israelis were expected to congregate during millennium celebrations on Jan. 1, 2000.

Over the past 18 months, U.S. Customs Service agents looking into bin Laden's money trail established that Almarabh and Hijazi had engaged in financial deals with Ahmed Alghamdi and Satam Al Suqami, two of the men who hijacked planes that took off from Boston and slammed into the World Trade Center's twin towers Sept. 11, law enforcement sources said.

Based initially on tips provided by Jordanian investigators, Customs agents for months traced money flowing from several Boston banks to banks overseas, where officials believe the funds were intended for bin Laden's network.

In the hours after Tuesday's bombings, investigators searched their files on Al Suqami and Alghamdi, noted the pair's ties to Almarabh and launched a hunt for him.

On Sept. 18, agents went to what they thought was Almarabh's home in Detroit. He was long gone, but agents arrested the three men there on charges of possessing fraudulent identification papers. Officials said they found what they considered suspicious items in the apartment, including a day planner with notations in Arabic about an "American base in Turkey" and "American foreign minister," and crude drawings of jetliner flight paths.

Investigators also established other connections between the two Boston cab drivers and the group that hijacked the planes. An FBI document circulated among law enforcement agencies last week noted that Hijazi, who is in a Jordanian jail, had shared a telephone number with another hijacker, Hamza Alghamdi. The document also said Hijazi was an "associate" of Almarabh.

These various connections not only suggest that investigators are probing ties between bin Laden and the hijackers, but also that federal authorities knew about some of those associations long before the bombings.

A federal investigator described Almarabh as "a player with bin Laden," but authorities said they have no evidence he played any direct role in last week's terrorist strikes. Almarabh was unavailable for comment, and efforts to identify his lawyer in Illinois were unsuccessful.

In December, Almarabh was convicted of assault and battery with a knife during an argument with a roommate in Boston. He failed to appear to begin serving his sentence in March, and has been wanted since then.

"In the few months that I worked with him, he did not give any outward appearance of being upset with the American people," said Robert F. Menton, who acted as Almarabh's court-appointed attorney in the Boston assault case. "His appearance was not menacing."

Lately, Almarabh appears to have moved every few months or continually changed his residence on official documents -- at one point listing an address in Dearborn, Mich., that is a truck stop. He repeatedly claimed to Michigan state officials that he had lost his driver's permit and secured temporary driver's licenses without photographs.

He obtained such a license most recently on Monday in Three Oaks, Mich., near the Indiana border. Then he apparently traveled to Burbank, where he got a job as a clerk at the 7-Days Food & Liquor store.

One fact that has caught officials' attention is that in September 2000, he received a Michigan chauffeur's license that allowed him to haul hazardous materials. Sgt. Susan Fries of the Michigan State Police's hazardous waste unit said authorities had no indication what toxic waste companies he worked for, if any.

Hijazi, 35, was born in Los Angeles to Palestinian parents and grew up in Jordan. After studying business at California State University at Sacramento, he moved to Boston and became friendly with Almarabh. When Hijazi applied for a taxi license in Boston, he listed Almarabh as the person to contact in the event of an emergency, a law enforcement source said.

Last September, Hijazi was convicted in absentia in Jordan of helping to lead the planned terrorist bombings. Human rights activists have charged that Jordanian authorities tortured some of the defendants. But Almarabh was subsequently arrested in Syria and returned to Jordan, where, under that country's laws, he is to be retried.

In the original trial, he was convicted of the bomb plot but acquitted of being a bin Laden lieutenant, though U.S. and Jordanian officials still maintain bin Laden was behind the plot.

After the trial, officials in Amman sent information back to Washington saying that Almarabh and one of the men who later participated in the hijackings were associates of Hijazi, a law enforcement source said.

On Wednesday, FBI agents in Los Angeles detained another man, Tarak Mohamed Fayad, apparently on immigration charges. He had lived with Hijazi in the Boston suburb of Malden.

Authorities also have investigated a third Boston cabbie, Bassam Kanj, who was a Hijazi friend and died last year in a gun battle in northern Lebanon between Islamic militants and the Lebanese army. Lebanese newspapers identified him as a bin Laden lieutenant.

Meanwhile, a document containing names of suspects that was sent to banking officials this week by the FBI lists alleged hijacker Khalid Al-Midhar as "alive." Al-Midhar is believed to have piloted the flight that crashed into the Pentagon. FBI and Justice Department officials declined to comment on the document, but the notation adds to uncertainty over the identities of 19 men listed as hijackers by the FBI.

FBI Director Robert S. Mueller III acknowledged yesterday that investigators were unsure whether some of the hijackers stole the identities of other people. Saudi government officials say they have confirmed that at least two of the terrorists used the names of law-abiding Saudi citizens.

In other developments yesterday:

* Mueller, joining Attorney General John D. Ashcroft in a visit to the United Airlines Flight 93 crash site in Shanksville, Pa., said the cockpit voice recorder recovered from the wreckage caught some conversation before the jet slammed into a hillside. Mueller added that investigators were "transcribing and translating the dialogue, what little there is."

* Law enforcement officials said a man detained over the weekend in San Diego was flown to New York for questioning about Al-Midhar and suspected hijacker Nawaq Alhazmi. The officials identified the man as Omer Bakarbashat and said authorities were interested in questioning him about time he may have spent with the two men, the Associated Press reported.

* A student at the University of Oklahoma has been detained by the Immigration and Naturalization Service because of a potential link to Habib Zacarias Moussaoui, a former flight school student with alleged ties to bin Laden, a local attorney said. The student, Hussein Attas, 23, was detained on the day of the attacks, according to Mitchell Gray, who is seeking to represent him.

Gray said Attas, a Saudi, may have driven Moussaoui to Minnesota, where Moussaoui was arrested in August after seeking commercial flight training despite a lack of experience. Gray said INS officials have rebuffed his attempts to reach Attas. INS officials in Oklahoma could not be reached for comment.

* The Justice Department retracted its report Wednesday that 115 people connected to the investigation were in INS custody on immigration violations. The number is 76, officials said.

Staff writers Dan Eggen, Caroline E. Mayer, Scott Higham, Karen DeYoung, Ceci Connolly and Lois Romano contributed to this report. Correspondent Howard Schneider reported from Cairo. Staff writer Robert Pierre reported from Chicago, and special correspondent Pamela Ferdinand reported from Boston.

Nabil Almarabh, 34, who used to drive a cab in Boston, is wanted for a probation violation in connection with a stabbing there in May 2000.