U.S. officials said yesterday that despite the apparent murder of an American librarian in Lebanon they do not believe the danger to other American hostages there has increased because of this week's raid on Libya.

The officials, while acknowledging that the chaos of the Lebanese civil war makes any prediction uncertain, noted that at least four of the missing Americans are believed held by an extremist Lebanese Shiite Moslem group hostile to Libyan leader Muammar Qaddafi and said it would therefore seem illogical for their captors to harm them out of sympathy for Libya.

Unlike these four, Peter Kilburn, 60, a librarian at the American University in Beirut who disappeared in December 1984 and whose body was found Thursday, was thought to have been the prisoner of another of Lebanon's free-lance terrorist groups. The officials, who have had much sketchier information about Kilburn than the other U.S. hostages, said it is possible that he was held by a Libyan-controlled group.

The new concern about the hostages arose as President Reagan denied that the United States staged the air strikes in hopes that Qaddafi would be killed in the bombing of his command post in Tripoli.

"We weren't out to kill anybody," Reagan told reporters outside the White House as they shouted questions about a Washington Post report that Qaddafi was a target of the attack. Secretary of State George P. Shultz said Thursday that the administration hoped the raids might trigger an internal revolt against the Libyan leader, but other administration officials said they did not know Qaddafi's whereabouts at the time and were not trying to kill him.

Intelligence sources said yesterday that Qaddafi remained in control of the Libyan government and that any internal rebellion had been put down. The sources said the long-range impact of Tuesday's raid cannot be measured because, as one put it, "We do not have a good handle on what is going on inside Libya."

The sources said they were especially interested in the Soviet Union's reaction to the raid. "The Soviets have not committed themselves, really, and we believe they want to distance themselves from what [Qaddafi] may do in retaliation," one noted.

Attempts to gauge whether Libyan calls for revenge might endanger the hostages in Lebanon are complicated by the fact that most Lebanese Shiites believe Qaddafi was responsible for the 1978 disappearance of Iman Mousa Sadr, the leading Shiite religious figure in Lebanon. This has resulted in strong anti-Qaddafi feeling among the Lebanese Shiites, but U.S. and diplomatic sources said that Libya nonetheless has been able to use its oil wealth to purchase the cooperation of some terrorist gangs in the Beirut area.

According to the officials, the U.S. belief is that some of these gangs abducted Kilburn and William Buckley, a U.S. Embassy political officer whose death was reported last October but has not been confirmed. However, the officials stressed, it has never been clear whether the groups that seized Kilburn and Buckley were controlled by Libya.

The group believed to hold the other four American hostages, the Islamic Jihad, wants to use them as bargaining chips to obtain the release of its members imprisoned in Kuwait for terrorist acts. The Islamic Jihad is understood to share the Shiite antipathy toward Libya, relying on Syria and Iran for support.

Although U.S. officials said privately yesterday that there is a "presumption" that Kilburn is dead, the administration said it could not confirm this without "positive forensic identification." The officials said the body will be flown to an American military hospital in West Germany and checked against Kilburn's medical records, a process they estimated will take several days.

Relatives of the other U.S. hostages, briefed on the information available to the administration, said the air strike against Libya left them fearful and uncertain.

Peggy Say, sister of Terry A. Anderson, 37, an Associated Press correspondent kidnaped in March 1985, said on the "CBS Morning News" that she does not believe Reagan considered the hostages' plight before ordering the raid. "It was an act almost designed to put them blatantly in danger," she said.

John Jenco, brother of the Rev. Lawrence Martin Jenco, 50, head of the Catholic Relief Services in Lebanon who disappeared in January 1985, said in a telephone interview from Joliet, Ill., that his family believes the administration is doing its best to free the hostages. But he added: "We knew the bombing of Libya would raise the possibility of retaliation. In our family, every phone call makes your heart go down right into your shoes."

Defense Secretary Caspar W. Weinberger said yesterday that the attack was approved reluctantly, as a last resort, and indicated that it would not have been necessary if European allies had cooperated in imposing economic sanctions against Libya.