Pfizer - the company behind brands such as Lipitor, Viagra and Celebrex - retains around 20 consultancies to handle its UK product PR and medical education.
Pfizer is now drawing up lists of 'preferred' and 'approved' agencies from which product comms managers will have to select.
Preferred suppliers are likely to be given work without competitive pitches. They will secure a place on the list after agreeing 'negotiated rates' and 'volume discounts' with Pfizer.
About 15 of the approved agencies will make up a second tier of suppliers that will have less detailed agreements.
Pfizer UK head of product comms Sarah Mathieson, who is driving the review in consultation with the firm's procurement department, told PRWeek: 'This is about ensuring quality, best practice and standardisation. We want to benefit from economies of scale.'
But Mathieson added: 'This is not about cutting costs; we are not going to change our overall annual spend on PR and medical education.'
The review is aimed at bringing consistency between agencies in areas such as what staff at different levels should bill per hour for work and even the costs of writing a press release.
Mathieson aims to confirm the lists by 4 October, although contracts with agencies could take until December to finalise.
The roster will then be informally reviewed every six months.