Diageo is to sell the Bushmills whisky distillery in County Antrim to Casa Cuervo of Mexico, in return for full ownership of Tequila Don Julio.
As part of the deal, Diageo will also buy back the distribution network for Smirnoff in Mexico from Casa Cuervo.
The transaction will result in a net payment of £256m to Diageo upon completion, which is expected in early 2015 subject to certain approvals.
Diageo, which also owns Guinness, Smirnoff, Harp and Baileys, already owns 50% of Don Julio which is described as being the oldest and most prestigious tequila company in the world.
Diageo has also just confirmed the sale of its whisky brand, Whyte & Mackay to Filipino drinks giant Emperador, in a deal worth around £430m. The deal was first publicised earlier in the year, but has now been officially confirmed.