The company will invite agencies to pitch through the London office of Roth Observatory International.
McCain denied that it had launched or was planning to launch a creative review when quizzed by Campaign three weeks ago.
In a statement on Wednesday, McCain said it was holding a review "in light of the changing nature of its needs from an agency partner".
BMB will repitch for the account, which it picked up in 2006. The agency’s founder Trevor Beattie was instrumental in TBWA winning the account in 2003 when he was its chairman and then won the business again after launching BMB.
McCain’s digital business, which was captured by TMW in May, is not affected.
Enquiries about the review should be directed to Lucinda Peniston-Baines, a managing partner at Roth Observatory.