WASHINGTON (AP) _ The Army Corps of Engineers has misused its emergency aircraft to fly officials at high cost to meetings and ceremonies around the world, sometimes improperly accompanied by their wives, an Army audit says.

''Virtually all of the flights were for routine matters and could have been accomplished with commercial aircraft,'' the Army Audit Agency said in a report released by Rep. Mike Synar, D-Okla.

''The average cost of using corps-owned aircraft was significantly higher than commercial flights ... to the same locations,'' the auditors said. ''The corps should sell their aircraft and use commercial transportation.' '

The report said taxpayers could gain $6.4 million from the sale and eliminate $1 million a year in corps travel expenses.

The report, which is being disputed by the corps, focused on the three aircraft owned by the corps' civil division, which builds water development projects in this country and provides advice to other nations.

The auditors said the corps' brass told Congress that the aircraft, including a Washington-based, 14-passenger executive jet, are necessary for rapid response to emergencies and natural disasters and for visits to remote projects.

But in 1984, all but one of 254 flights ''were for routine meetings, staff visits and inspections, training and ceremonies,'' according to the report. It said the corps could have cut its travel bills 71 percent by using commercial and charter flights.

And despite an Army policy discouraging use of government planes for overseas travel, the executive jet spent 52 percent of its flying hours winging to places like the South Pacific and Europe, the report said.

''Corps aircraft were improperly used to transport dependents of employees at government expense,'' according to the auditors, who said the problems cited in the report for 1984 and 1985 ''were essentially unchanged'' in 1986.

The report said that in June 1984, six dependents who were not authorized to travel at taxpayer expense accompanied five corps employees on an agency aircraft to Helsinki for a conference of the Permanent International Association of Navigational Congresses (PIANC).

At a House subcommittee hearing last week, Synar noted that the itinerary for wives included sightseeing, a fashion show and visits to an old cottage and a candy factory.

A corps official says the wives' presence was justified. Lt. Gen. Elvin Heiberg III, the chief of engineers, said they satisfied the Army's requirement that their presence be necessary for official functions or provide diplomatic or public relations benefits.

''The ladies accompanied members of the delegation to dinners and receptions,'' including one held at the U.S. Embassy, Heiberg said.

''I don't buy that,'' responded Synar, who said wives accompanying corps officials to PIANC's 1985 meeting in Brussels had an itinerary of ''excursions and visits to leading Belgian cities'' and ''exploring Belgian gastronomy.''

''I guess it was a real disappointment that the 1986 PIANC convention was held in Portland, Ore.,'' said Synar, chairman of the Government Operations subcommittee on environment, energy and natural resources.

The audit report said the corps has ''largely ignored'' Army policy, based on a 1983 presidential directive, designed to limit administrative, overseas and dependent travel on military aircraft.

It cited an April 1984 trip by 13 people, including three retired generals and six dependents, from Washington to St. Paul, Minn., for a three-day meeting of the Society of American Military Engineers.

''While this conference appeared to be business related, it had no direct impact on the corps' mission,'' the report said.

It said the corps also spends money unnecessarily by having senior officials accompanied by subordinates not needed at meetings but taken along because an aircraft had empty seats.

In comments in the report, the corps said very little of the travel on its aircraft could be done as efficiently using scheduled commercial airlines. The corps said its aircraft provide greater security against terrorism; that a sale of the three planes would bring only $4 million; that travel by wives was properly approved by the chief of engineers, and that 85 percent of all 1986 flights were essential.