Qatar Airways previously worked with Perowne Charles Communications, which split into The PC Agency and Perowne International last year.
Engage, which was launched earlier this year by the agency better known for political and corporate work, has been tasked with creating a series of campaigns to promote Qatar Airways to stakeholders in the UK, the carrier's UK & Ireland country manager Morena Bronzetti said.
Engage partner Charlie Hampton told PRWeek that Qatar Airways was one of the agency's "flagship travel and tourism clients". The agency's other travel clients include South African Tourism and Bristol Airport.
Engage launched its first campaign for Qatar Airways on 30 March to mark the first anniversary of its services from Birmingham Airport.
Hampton, who is leading the account, said: "Given that the gift for a first anniversary is 'paper', the campaign for Qatar Airways, which was done in partnership with Birmingham Airport, was based around a treasure hunt for paper aeroplanes for passengers departing on Qatar Airways' flights."
As part of the campaign, Engage also created a Snapchat geofilter for the airport "to drive excitement in advance of the treasure hunt", Hampton said.
Qatar Airways flies from Heathrow, Birmingham, Manchester and Edinburgh in the UK, and Hampton said further campaigns would be rolled out across these airports in Q2.
Bell Pottinger was ranked as the 13th largest agency in the UK, according to the new PRWeek Top 150 league table.