The agency will manage a brief covering consumer and corporate comms, as well as public affairs and crisis management.
It is understood that incumbent Weber Shandwick did not repitch.
Work on the brief, which is understood to include a focus on building on an established reputation for customer service, will be led by agency MD Nadia Gabbie.
London is a key destination for the airline, which is currently facing growing competition from Middle Eastern carriers on routes to Europe and America.
However, according to reports on the Travel News website, it is cutting seats on routes to the city from the end of October.