The crew of a Marine Corps jet that struck a ski lift in Italy, killing 20 people, did not have a map that showed the ski-lift cable, the Pentagon acknowledged yesterday.

A Pentagon spokesman, Lt. Col. Stephen Campbell, said the flying chart used by the military shows terrain features but does not include obstructions that are less than 200 feet high, such as the lift. The chart was produced by the United States and Italy in 1992, he said.

A separate book used by U.S. military pilots, the Flight Information Publication, is updated every 20 days and specifically states that pilots in the area where the ski lift is located were to maintain a minimum altitude of 1,000 feet, Campbell said.

The New York Times reported yesterday that the pilot of the EA-6B had flown into an area the Italian government said was off course and was violating Pentagon rules by failing to stay at least 1,000 feet above the ground.

The accident has strained relations between the two nations and the Italian and American militaries are conducting a joint investigation to determine whether any of the jet's crew or its commanding officers should face charges. Italian civilian prosecutors are conducting a separate investigation.

While the Feb. 3 flight was the crew's first over an Alpine valley in northern Italy near Cavalese, the pilot -- Capt. Richard J. Ashby -- did not have the Italian military charts provided to his commanders that marked the ski lift, which is also noted on road maps.

Instead, the paper said, the Pentagon had given the four-man crew an American military chart that did not show the ski-lift cable. Marine officials would not explain why the Italian charts were not used, the Times said.