Beijing/Bangalore, April 12 Alibaba Group Holding Ltd said today it has agreed to buy a controlling stake in Southeast Asia online retailer Lazada Group for about $1 billion, its biggest deal overseas, as the Chinese e-commerce giant seeks fertile new turf while growth slows at home. Lazada, founded by Germany’s Rocket Internet in 2012, is headquartered in Singapore and also operates in Malaysia, Indonesia, the Philippines, Thailand and Vietnam. That affords Alibaba a chance to tap region’s growth potential, but the market is also competitive and fragmented, with only a tiny fraction of total retail sales currently conducted online. “Southeast Asia has a lot of overlap with China in terms of consumer habits, intra-regional trade and tastes,” said Duncan Clark, chairman of investment advisory firm BDA China. “Rocket in this case has managed to create a successful, multi-market player in a region which needs scale and breadth to be viable. This has obvious appeal to Alibaba.” Under the deal — Alibaba’s biggest overseas investment so far, according to Thomson Reuters data — the Chinese firm will buy about $500 million of newly issued Lazada shares. The rest will be bought from current shareholders. These include Britain’s biggest supermarket operator, Tesco Plc, which said it would sell an 8.6 per cent stake for $129 million, valuing Lazada at $1.5 billion. Rocket and Investment AB Kinnevik will also sell shares. Neither Alibaba nor Lazada specified the size of the stake purchased, but the sales imply a two-thirds holding.