Michele Meeker, associate director of respiratory corporate affairs, confirmed the search and said that the company would make a decision immediately, likely within the week.
She declined to say how many agencies the company had heard pitches from and would not name the outgoing firm.
The franchise includes products, such as Accolate, Oxis, and Symbicort, used to manage asthma and chronic obstructive pulmonary disease. Symbicort is a pressurized metered-dose inhaler that was approved by the FDA in July 2006. It has since seen slower than expected initial sales, though hopes remain high for the product.
AstraZeneca has recently been forced to fend off concerns over its pipeline, with its stock dipping lower as Wall Street analysts worry that the company will suffer due to competition from cheaper generic drugs.
Company executives have said the June acquisition of MedImmune will bring in added vaccine and biotech drug candidates.