British Airways has placed an order for 36 new aircraft - the largest the airline has made since 1998.
BA says the new planes will allow it to increase capacity
BA will buy 12 Airbus A380 superjumbos and 24 Boeing 787s, to be delivered between 2010 and 2014, an order which has a list price of $8.2bn (£4.1bn).
The group also has options to buy seven more A380s as well as a further 18 Dreamliners from Boeing.
The new planes would be "greener, quieter and more fuel efficient" with much lower CO2 emissions, BA said.
The new planes will replace 34 of BA's existing long-haul fleet.
The carrier added that the new orders, including the options, would give it the ability to increase its capacity by 4% a year.
Both types of planes will be powered by Rolls-Royce engines, the airline said.
The A380 superjumbos and 787 Dreamliner planes will lead to greater efficiencies, offering "significant economic benefits with lower costs per seat", the airline said.
The A380 will be used to provide more passenger spaces in key markets, particularly in flights from Heathrow.
Meanwhile, the 787 will be used to start new routes and increase the number of flights made.
"These new aircraft will continue our commitment to deliver the best travel experience to our customers," said BA chief executive Willie Walsh.
"This order builds upon our recent investment in improving the customer experience through (Heathrow) Terminal 5, the new Club World cabin, in-flight entertainment system and ba.com."
While BA declined to say how much the orders were worth, it did say that it had arranged a $1.5bn debt financing facility with a group of banks to cover the order.
News of the deal should provide a boost to struggling Airbus - owned by European aerospace group EADS - which has been hit by costly delays to production of the A380.
EADS shares rose 2% on the news in early trade on the Paris market to 21.50 euros.
Mr Walsh said that his company came under no political pressure to choose either Airbus or UK firm Rolls-Royce for the orders.
"There was no contact [from politicians], be it formal or informal," Mr Walsh told reporters.
"The decision was made in the best interest of British Airways. In the engines, the choice of Rolls-Royce was because British is best."