Diageo, the world's largest spirits maker, said it had agreed to acquire control of United National Breweries beer business in South Africa, buying the remaining 50% stake it did not already own.

Diageo, the maker of Guinness, Smirnoff vodka and Johnnie Walker whisky, struck a deal in January 2013 to buy half of the company, which owns United National Breweries' traditional sorghum beer business in South Africa.

Today it said it would pay an initial $22 million to Pestello Investments Inc for the remaining half. 

The deal includes a potential earn-out payment of up to $14m and is conditional on consent from the South African competition authority.