Bob Ivell, executive chairman of the firm, made the announcement at the ALMR's 20th anniversary conference yesterday (Thursday).
Ivell said: "I have always had a view that as an industry we don't speak with one voice enough and I think that is really really important, and so I am pleased to announced that Mitchells and Butlers will be joining ALMR."
The news is a significant boost for the trade association which last month announced it was merging with the Bar, Entertainment and Dance Association (BEDA).
By Neil Gerrard
E-mail your comments to Neil Gerrard here.
Looking for a new job? Find your next job here with Catererandhotelkeeper.com jobs