Thorntons has begun supplying products to Massmart, the Walmart-owned South African retailer.
The chocolatier supplies a plethora of UK retailers including Tesco but the move is significant for the retailer which has long harboured ambitions to build a strong international arm.
Thorntons confirmed that it is working with Massmart but declined to comment on the details of the agreement.
Thorntons international arm is currently dominated by business in the Middle East.
The chocolatier sells its products, produced at its headquarters in Derbyshire, through its wholly-owned stores, franchise operations and through other retailers via wholesale agreements.
Massmart, which was acquired by Walmart last year, has 330 stores as well as an extensive wholesale business.
Thorntons has faced a difficult time in the UK where a tough market and stiffening competition has hit trading.
The retailer’s chief executive Jonathan Hart is enacting a strategy to slim down Thorntons’ store estate and improve its online presence.
In July, the retailer reported a like-for-like sales increase 0.7% in the fourth quarter and the retailer is due to report its full-year results for the 53 weeks to June 30 next Wednesday.