The Defense Department, in its first official evaluation of the April 15 bombing raid against Libya, acknowledged yesterday that three bombs went astray and "impacted in the vicinity of the French Embassy" while another two missed the Benghazi Barracks and "damaged two civilian houses plus some adjacent walls and outbuildings."

The Pentagon statement said "this is the only collateral [unintended] damage we can say may have been caused by U.S. weapons on the basis of a careful examination of photography of the target area. Any other damage claimed by the Libyans, if actually true, most likely resulted from Libyan ordnance falling back to earth."

The acknowledgment of damage outside the military targets contrasts with initial statements by Defense Secretary Caspar W. Weinberger after the night raid. When asked at a White House news conference about reports that the French Embassy had been hit, Weinberger replied: "That would be, I think, virtually impossible."

The Defense Department's 2 1/2-page statement gave no estimate of Libyan military or civilian casualties in the raid by Air Force F111 bombers based in Britain and Navy A6E bombers from the aircraft carriers USS America and USS Coral Sea in the Mediterranean. There also was no explanation of why some of the "precision guided" bombs missed their targets.

"Collateral damage was held to a minimum," the Pentagon said. "Only 1 to 2 percent of the bombs impacted in civilian areas . . . . While complete destruction of each of the five targeted installations was never envisioned, all targets were hit and received very appreciable damage. The military objective of our operations was to inflict damage to headquarters associated with terrorist activities, terrorist facilities and military installations that support Libyan subversive activities . . . . The results of the strike met the established objectives."

Libyan officials have claimed widespread damage to civilian areas. Staff Maj. Abdul Salaam Jalloud, the second-ranking official in the Libyan government, told reporters on April 18 in Tripoli that 37 persons were killed in the raid, including 36 civilians, and that 93 persons were injured. Libyan officials listed among the casualties Libyan leader Muammar Qaddafi's adopted year-old daughter, Hana, who they said was killed, and his two youngest sons, reportedly injured.

One principal target for 2,000-pound bombs was Qaddafi's compound, which includes the family residence, his private tent and the Bab Azizzia Barracks housing his elite guard. In discussing the barracks, the Pentagon said: "Inasmuch as the entire complex was, in one way or another, related to Qaddafi's command and control of terrorism, the entire complex was considered targetable. Damage to Qaddafi's headquarters and contiguous working spaces was substantial."

A high-ranking U.S. official familiar with the targeting plans told The Washington Post after the raid that nothing in the compound was put off limits, in contrast to the restrictions against bombing the residence of North Vietnamese leader Ho Chi Minh during the Vietnam war.

"We hoped we would get him," the official said of Qaddafi, "but nobody was sure where he would be that night." Intelligence officials had put the odds of killing Qaddafi at no better than 4 to 1, according to informed sources.

In a news conference Wednesday, President Reagan said that although Qaddafi was not personally targeted "I don't think any of us would have shed tears" if the Libyan leader had been killed.

Reagan denied planning a new raid against Libya. But Pentagon sources confirmed a CBS report that contingency planning includes placing Libyan targets into the computer systems of submarine-launched cruise missiles as an alternative to another bombing raid, in order to avoid risking pilots and planes. An F111 and its two-man crew were lost in the April 15 raid.

An administration official who has read transcripts of tape-recorded conversations between the U.S. fliers during the Tripoli portion of the raid said that the pilot of the doomed F111 suddenly exclaimed, "I'm hit!" "Sorry about that," came a garbled response, apparently from another pilot.

The Pentagon statement said the three bombs that exploded near the French Embassy "were probably from one F111." Informed military officials said that some of the 2,000-pound bombs intended for Qaddafi's compound went astray when two F111 bombers flew too close together, causing one of them to pull away from his computer-designated drop point to avoid the burst and smoke created by the lead plane's bombs.

The Pentagon did not explain yesterday why at least two Navy bombs missed the Benghazi Barracks, saying only that they were "near misses" that fell some 700 yards off target.

The Pentagon also did not address what military sources said was a case of mistaken identity when an F111 crew bombed a high school for naval cadets at the Sidi Bilal naval complex outside Tripoli, instead of the alleged terrorist training school for swimmers and divers nearby. The bombs damaged "the swimmer-diver training complex," the Pentagon statement said.