American Airlines says it has placed the largest order for new passenger planes in aviation history.

The U.S.-based carrier announced Wednesday it will pay almost $40 billion to buy 460 new planes over five years — part of an effort to revamp its aging fleet and save money on fuel costs.

The move will also give European planemaker Airbus a bigger share of the U.S. market

American Airlines' fleet is currently made up of planes made by Airbus' U.S.-based rival, Boeing. But American said more than half of the new planes will be Airbus A320s — some of which have 15 percent better fuel efficiency.

The carrier says the other 200 planes will be Boeing 737s. About half of the Boeing planes will also come with new, more fuel efficient engines.

American Airlines is the fourth largest U.S. carrier but flies some of the country's oldest planes. The company said its aging fleet, combined with rising fuel costs, caused it to lose $286 million for the April through June period.

Europe's Airbus and U.S.-based Boeing are the world's two largest planemakers and have been competing intensely for new sales.

Airbus has outsold Boeing for the past three years.