Etihad Airways has ordered an additional 10 Boeing 787-9s, making it the largest customer for the twinjet's variant.
Abu Dhabi's national carrier also signed up for two Boeing 777 Freighters, bringing the list price of the combined purchase to $2.8 billion.
The airline, which cancelled an order for four 787-9s this year, now has a total of 41 on order. Its new freighter order also brings its current 777 backlog to 12.
"Our decision to expand our Dreamliner fleet is testimony to Etihad's commitment to operating one of the youngest and most fuel efficient fleet in the skies," said Etihad Airways CEO James Hogan in a statement.
"Both the Boeing 787 Dreamliner and the 777 Freighter offer highly attractive operating economics and will facilitate our global expansion plans by allowing us to transport passengers and cargo into new global markets from our hub in Abu Dhabi," he added.
The airline has in the past 12 months added six aircraft. Seven passenger aircraft - three Airbus A320s and four 777-300ERs, will join its fleet next year. It currently operates 63 aircraft, including five freighters.
The airline's first A380s and 787-9s are due to arrive in 2014, the latter having slipped from the original 2013 schedule in the wake of delays in the aircraft's development.