Spain's Telefonica and Chinese mobile operator China Unicom will deepen their strategic alliance by buying an additional $500m (£312.5m) stake in each other. The two companies, which together have more than 550m clients in Europe, Asia and Latin America, are exploring joint investments in parts of Asia and Africa where they are not already present. After the new purchase, Telefonica's stake in China Unicom will rise to 9.7 per cent, while China Unicom's ownership of Telefonica will reach a total of 1.37 per cent. China Unicom, which will purchase 21.8m shares of Telefonica in the coming days at an agreed on price of €17.16 per share, will get a seat on Telefonica's board. Telefonica will buy $500m worth of China Unicom shares from third parties over a nine-month period.