The price of the deal to purchase Quimiproductos, a wholly-owned subsidiary of Fomento Económico Mexicano, was not disclosed.
With 2011 revenue of $35m, Quimiproductos serves beverage and brewery customers in Mexico and several Central and South American countries.
Completion of the transaction is subject to regulatory clearance and standard closing conditions.
Douglas M. Baker, Jr., Ecolab's chairman and chief executive officer, said: "This acquisition will help us to build scale, strengthen our core product offerings and improve service capabilities to our beverage processing customers in the fast growing Latin America region.”