MCBD has seen off competition from a shortlist of seven agencies pitching for the retailer's business, including BBH, BMB, Kitcatt Nohr and Isobel.
MCBD has held the account for two years since it merged with previous incumbent HOW last November.
The review comes six months after a rejig of the retailer's senior management, including the departure of marketing director Christian Cull to BSkyB and the promotion of Mark Price to managing director. Cull has not been replaced, so the review has been handled by buying director Richard Hodson
Waitrose has 186 stores in the UK and a 4% market share. In the six
months to the end of July, profits rose 29.7% to £140m.
The retailer's ads highlight its commitment to sourcing locally produced
MCBD declined to comment.