Creativebrief, which is overseeing the agency hunt, has approached a number of undisclosed shops with a view to drawing up a shortlist to pitch for the business.
Freesat has previously worked with Fallon, which produced a print and poster campaign for its launch in May. The agency will not be repitching for the business.
The appointment of a new above-the-line agency will mark the latest in a number of agency appointments. Since the service was given approval by the BBC Trust last April, Freesat has appointed MPG to its media business, Agency Republic to produce its digital advertising and Billington Cartmell to handle its retail activation activity.
Freesat also kicked off a search for a direct marketing agency in May.
The review follows the recent addition of 18 new radio and TV channels to Freesat's existing offering of BBC and ITV channels, including Zone Horror, Russia Today and Capital Radio.