UK supermarket chain Tesco --  the world's third-biggest retailer -- has sold 50 percent of its shares in Tesco Japan to Aeon, Japan's largest retailer.

The shares were sold for a "nominal sum," Tesco said in a notice to the London stock exchange.

Following the sale, Tesco Japan will become a joint venture between Aeon and Tesco. Tesco has agreed to invest around £40 million (€49.2 million/$62.8 million) into the venture to "finance further restructuring," before fully exiting the business.

Tesco announced in 2011 that it would pull out of Japan.