WASHINGTON, Oct. 29 — A top C.I.A. official secretly traveled to Damascus this month to talk to Syrian intelligence officials about helping the United States investigate and defeat Osama bin Laden's terrorist network, according to American officials.

The senior official, from the Directorate of Operations, the clandestine- espionage arm of the agency, met the officials in Syria, which is on the State Department list of nations that sponsor terrorism.

Syria has a long history of cooperating with and sponsoring Islamic militant groups, including Hamas and other Palestinian organizations, while battling others. As a result, the Syrians may be able to provide insight into the connections among Islamic terrorists across Europe and the Middle East.

At least one figure who has emerged from the investigation into the attacks on Sept. 11 is a Syrian- born executive in Germany who German authorities suspect may be a link between the hijackers and Islamic militants in Germany.

The executive, Mamoun Darkazanli, has been included on a list of 27 individuals and organizations whose assets were frozen by the United States on the ground that they provided money to Mr. bin laden's group, Al Qaeda.

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The substance of the discussions between the C.I.A. and Syrian intelligence officials could not be determined. But the mere fact of the meeting represents a significant shift in relations between the United States and Syria.

The Damascus meeting follows a meeting in London between State Department and C.I.A. officials and the chief of Libyan intelligence. The State Department said that meeting was held to discuss Libya's compliance with its obligations under United Nations resolutions that deal with the bombing in 1988 of Pan American World Airways Flight 103 over Lockerbie, Scotland. Other officials have indicated that Libya's possible cooperation on counterterrorism efforts was also broached. The results of that discussion are not known.

Since Sept. 11, C.I.A. officials have opened communication lines with intelligence officials from several nations that Washington has in the past accused of providing state support for terrorism. Among the most unlikely is Sudan, where the United States destroyed a pharmaceutical factory that was suspected of being involved Mr. bin Laden's efforts to obtain chemical weapons. Mr. bin Laden lived in Khartoum from 1991 until 1996.

Now Sudanese officials are helping the Federal Bureau of Investigation and the Central Intelligence Agency in their counterterrorism operations. The Sudanese say they have arrested at least one major terrorist suspect connected to Al Qaeda.

The new effort to work with America's former adversaries in the campaign against terrorism arises as the F.B.I. has begun to run out of leads at home in its investigation of the September attacks and finds that it has to focus on following the trails of the hijackers and their accomplices overseas.

For the bureau, that means an increasing reliance on foreign governments — and the intelligence agency's relationships with foreign intelligence services — to track down potential suspects. Since Sept. 11, at least 40 countries have made terrorism-related arrests. American officials say they believe that those arrests may have forestalled attacks on American targets.

The effort to reach out to Syria is being made as the United States has begun to acknowledge that the traditional patterns of Middle East terrorism are rapidly evolving and that many of the traditional state sponsors of terrorism do not support what is widely seen as the main terrorist threat to the United States — Mr. bin Laden and Al Qaeda.

The State Department reports that Syria continues to provide a safe haven and support for several Palestinian terrorist groups, including the Popular Front for the Liberation of Palestine, either on its own territory or in areas of Lebanon under Syrian control.

American officials say they believe that the Syrian government opposes Al Qaeda, which represents an Islamic militancy similar to one that Syria worked hard to stamp out there in the late 1970's and early 80's.

In Africa, Libya has been hoping for years to get escape the sanctions tied to its involvement in the Pan Am 103 bombing. Libya surrendered two of its agents who were accused in that attack. They were tried in a Scottish court at The Hague.

The Libyan leader, Col. Muammar el-Qadaffi, has also expelled the Abu Nidal terrorist organization in order to improve his international image, and some American officials believe that he has no interest in supporting Mr. bin Laden and Al Qaeda.

For countries like Syria, where the United States may not be particularly popular, secret intelligence cooperation allows it to "help us in ways that they don't need to acknowledge," said Robert M. Gates, who was director of central intelligence under President George Bush.

For the C.I.A., working with intelligence officials from countries that have supported terrorists in the past holds obvious risks.

American officials will have to determine whether the information provided by countries like Syria is biased in an effort to support some Syrian agenda that is not immediately apparent.

"While we need the intelligence very much, the trick is that some of the people we're sharing with are people with whom our partnership will be very limited," said Gregory F. Treverton, a former vice chairman of the National Intelligence Council, a group that oversees American intelligence analysis. "We are not close friends with all these nations. All the people we share with have their own interests. And they will cook the books to pursue their own interests."