American Will Park 25 Wide-Body Jet Planes : Airlines: United, meanwhile, wraps up talks on cutting back orders for as many as 60 aircraft through 1995.

In the first substantial fleet reduction by a major air carrier, American Airlines on Wednesday said it would ground 25 wide-body jets this year as part of cost-cutting efforts.

Meanwhile, United Chairman Stephen Wolf said his company had completed negotiations to cut back on its purchases of Boeing Co. aircraft and is nearly finished with talks to reduce purchases of General Electric Co. jet engines. Analysts estimate that United might cut nearly 60 jet orders during 1994 and ’95.

Analysts said the moves by United and AMR Corp.’s American Airlines represent the last major wave in a broad industry effort to reduce passenger-carrying capacity in response to the industry downturn that began with the 1990-91 recession.

“I think that the lion’s share of order cancellations is behind us,” said Samuel C. Buttrick, an airline industry analyst at Kidder, Peabody & Co.

American said it will remove the 25 McDonnell Douglas DC-10s from service between June and the end of the year. The 290-seat aircraft are used primarily between large cities, including Los Angeles, Dallas, New York and Miami.

“We will replace the DC-10s where they operate with narrow-bodied airplanes,” such as the Boeing 757, said Alton Becker, spokesman for American, which flies nearly 700 jets. Narrow-body jets serving some routes might be replaced with turboprop-driven American Eagle commuter airplanes.

Over time, service might be dropped entirely from some weaker markets, Becker said.

“This is all part of the transition plan to reduce and eliminate operations in weaker markets, and to concentrate in the stronger markets,” he said.

While U.S. airlines have canceled billions of dollars in aircraft orders, their fleets have continued to grow as they take delivery of previously ordered planes.

After accounting for the delivery of new aircraft, American’s decision to ground the 25 DC-10s will reduce its capacity by 3% this year--the first such decline in recent memory, according to an airline spokesman.

In contrast, American added nearly one new plane a week during 1990, according to industry estimates.

“This is the most significant cutback we have seen so far in this recent downturn,” said Andrew Nocella, an analyst at Avmark, a Washington, D.C.-based aviation consulting firm. “I think other airlines will do the same.”