American retail giant Walmart Inc. has agreed to pay $16 billion for a 77% stake in India’s largest start-up Flipkart, valuing the firm at about $21 billion in what is one of the largest acquisitions ever in the country. The deal will redraw the retail landscape in India as Walmart takes its domestic battle with arch-rival Amazon to the global stage. It will also give a massive boost to entrepreneurship and the start-up ecosystem, which has struggled to provide exits. The buyout is the largest-ever in e-commerce, according to data compiled by Bloomberg. It will see the exit of Flipkart's co-founder and chairman Sachin Bansal. The other co-founder Binny Bansal and other Flipkart shareholders will hold the remainder of the stake. The deal comes less than five years after Walmart exited India as a joint venture with Bharti Enterprises soured.