Tourism Northen Ireland is looking for an agency, or consortium of agencies, to work on campaign ideas, above- and below-the-line executions, media planning and buying, digital marketing, production, events and strategic tie-ups.
The brief, which Tourism NI estimates to be worth £14 million, will last for an initial period of two years but with the option of two one-year extensions.
Agencies that want to pitch for the contract have until 18 September to contact Tourism NI.
The tourism body has previously worked with AV Browne, a full service advertising and media agency with offices in Belfast. In 2014 the agency created a campaign that was narrated by Liam Neeson, the Hollywood actor who has starred in Schindler's List and Taken.
In June, Belfast Zoo took delivery of a "critically endangered dragon" as part of a stunt to promote Northern Ireland to worldwide fans of Games of Thrones, the fantasy TV series.
Tourism NI did not respond to requests for comment.