Boeing said on Thursday that British Airways finalised an order for 24 Boeing 787 Dreamliners, an order valued at $4.4 billion at list prices.
British Airways also has options for 18 more 787 planes and purchase rights for an additional 10, Boeing said in a statement.
British Airways had announced last September its selection of the 787 as part of its long-haul fleet renewal.
"The 787 is a fantastic aircraft and will be a welcome addition to our fleet," BA Chief Executive Willie Walsh said in a statement. "It will provide major environmental improvements in terms of global emissions, local air quality and noise."
The Dreamliner breaks new ground with a fuselage made of light-weight carbon composite, and is due to enter service next year.
"With lower operating costs and the range to fly to all our destinations, it will give us more flexibility when planning our route network and we are confident that our customers will enjoy flying on the aircraft," Walsh added.
Shares in British Airways were down 0.6 percent at 313.25 pence.