Burson-Marsteller is the incumbent agency on the business. It is not known whether it is one of around four firms to have pitched.
The US Food and Drug Administration late last year urged doctors to restrict their prescription of Advair and recommended stronger warnings be added to its packaging.
GSK disagrees with the FDA's view that the asthma medicine increases the chance of deadly complications, and a significant fall in prescriptions is believed unlikely to occur.
More information on Advair's risks may become available later this year, when GSK is reportedly expecting to unveil results from a study on death rates.
GSK rivals in the respiratory market include AstraZeneca, which makes Symbicort; Merck (Singulair); and Altana Pharma/Pfizer (Daxas). Ketchum continues to handle UK comms for GSK respiratory brands. Its contract is unaffected by the global review.
An appointment to the business is believed likely within weeks.