The move has put 18-year incumbent Keene Public Affairs on alert.
The state-owned carrier is reviewing its links with Keene as part of a wider organisational audit, said PR manager John Cotton.
Eight agencies have been asked to submit proposals and pitches are likely to take place in January, he added.
In October the airline reported a 50 per cent jump in half-year profits, with record revenues offsetting soaring fuel costs. The airline is the world's second biggest in terms of market value after Southwest Airlines.