Dubai - Dubai International, already the world's busiest airport by international passenger traffic, opened a new extension on Wednesday that will raise its annual capacity to 90 million passengers.
Dubai Airports said: "The opening of Concourse D is the result of a $1.2bn investment to enhance service and boost capacity for the more than 70 international airlines."
British Airways was the first airline to use the new concourse, connected by train to Terminal 1.
Dubai Airports CEO Paul Griffiths said: "Today (on Wednesday) we also announce our 2016 forecast which projects 85 million passengers will visit Dubai International this year."
Dubai International said it remained the world's busiest airport for international travel in 2015 with more than 78 million passengers passing through.
Dubai first announced it had overtaken Britain's Heathrow as the world's busiest airport for international passengers last year, after 70.4 million international travellers passed through its doors in 2014.
Situated on transcontinental air routes, Dubai is one of several Gulf-based airports to experience prodigious growth in recent years.
Around 100 airlines fly to more than 240 destinations from the international hub, which is also home to carrier Emirates.
Dubai's second airport, Al-Maktoum International, opened in 2013 and will be capable of receiving 120 million passengers a year once fully operational.