(Reuters) – Chinese e-commerce giant Alibaba Group Holding Ltd said on Tuesday it agreed to buy a controlling stake in online retailer Lazada for about $1 billion to expand its platform into Southeast Asia.

Alibaba would invest about $500 million in newly issued Lazada shares and acquire shares from shareholders of Lazada for a total of about $1 billion.

Lazada operates in Singapore, Malaysia, Indonesia, the Philippines, Thailand and Vietnam.

In a separate announcement, Britain’s biggest supermarket operator Tesco Plc said it agreed to sell an 8.6 percent stake in Lazada to Alibaba for $129 million.

(Reporting by Rama Venkat Raman in Bengaluru; Editing by Gopakumar Warrier)