Secretary of State George P. Shultz and Deputy Secretary John C. Whitehead acknowledged yesterday that the United States is aware of evidence that could link Syria to the aborted April 17 attempt to bomb an El Al airliner in London and a terrorist bombing last month in West Berlin.

Whitehead said the United States "has no reason to doubt" Israeli charges that Syria was behind the El Al incident. But both he and Shultz refused to speculate on whether the United States might strike Syria with the same kind of military and economic actions taken against Libya.

Several diplomatic sources have said the United States is aware that Nezar Hindawi, a Jordanian arrested by Britain on charges that he tried to plant a bomb aboard the El Al plane in the baggage of his Irish fiancee, told British interrogators that he was working for Syria.

Hindawi has said he was trained in Damascus, was given a Syrian passport issued under a false name and was escorted to London by a Syrian intelligence officer on a Syrian Arab Airlines plane, according to these sources. He also has asserted that officials of the Syrian Embassy in London helped him plan the El Al operation and supplied the bomb, which was discovered by security officers in the luggage of his unsuspecting fiancee, Anne-Marie Murphy.

Hindawi reportedly said that he was subsequently taken to a hideout apartment, personally congratulated by the Syrian ambassador and led to believe that he would be returned to Damascus. After the bomb was discovered, Hindawi reportedly told his interrogators, he began to fear that the Syrians might try to kill him, so he slipped away and surrendered to British police.

Hindawi told the British that his brother, identified as Ahmed Nawaf Mansour Hasi, had participated as a Syrian agent in the April 5 Berlin nightclub bombing that killed an American soldier and helped to provoke retaliatory U.S. air raids against Libya, according to the diplomatic sources. West German police subsequently arrested Hasi on suspicion of involvement in the nightclub incident; the authorities also said he had confessed to the bombing of the German-Arab Friendship Society in West Berlin on March 29.

Yesterday, however, Shultz and Whitehead avoided specific allegations and instead talked in general terms about "terrorism being reprehensible wherever it occurs," as the deputy secretary put it. They also cited the need for more investigation and said the situations are different because the evidence about Syria is not as unequivocal as it was against Libya.

Shultz, speaking on NBC's "Today" show, drew a contrast between Syria, which has denied the charges, and Libyan leader Muammar Qaddafi, who "bragged about terrorism." Whitehead, interviewed by United Press International, said there is reason to believe that Syrian President Hafez Assad is trying to suppress the terrorist groups that his government formerly supported.

Whitehead said the United States had received information about Syrian involvement from Israel and added: "It's their information, not ours, but we have no reason to doubt it."

Other U.S. officials, elaborating privately, said the information reportedly supplied by Hindawi had been made known to the administration by "a variety of sources." They said senior administration officials are reluctant to talk about it publicly for several reasons, including concern that it might hinder West German and British investigations and generate pretrial publicity that would prejudice the case being prepared by British authorities against Hindawi.

In addition, the officials said, the administration is wary of provoking a confrontation with Assad that could cause new tensions in the Middle East and indirectly lead to a military clash between Israel and Syria.

These officials noted that unlike Qaddafi, whose unpredictability makes him relatively isolated, Assad has the strongest armed forces of any Arab nation and, if provoked, can use his military power to pressure moderate Arab states such as Saudi Arabia and Jordan. Assad also could use his terrorist apparatus to foment dissension throughout the region, the officials added.

As a result, the officials said, there is a danger of Syria using these weapons to drive a wedge into the already troubled relations between the United States and moderate Arabs, and to make America's West European allies, which have started to take steps against Libya, again reluctant to cooperate with the U.S. drive against international terrorism.

In addition, the officials said, the United States believes that Syria has influence with terrorist groups holding four American hostages in Lebanon. Washington is reluctant to take steps that could make their situation more perilous.

Finally, the officials said, there is concern about creating a situation that might serve as a springboard for military clashes between Israel and Syria. In addition to its charges about the El Al incident, Israel recently has accused Syria of building tank and artillery trenches in southern Lebanon near the Israeli border.