Flipkart Online Services Pvt signed a pact with tycoon Gautam Adani’s conglomerate to help set up one of India’s largest logistics hubs and a data center, as the Walmart-owned e-commerce firm gears up to battle Amazon for a bigger slice of the local market. The tie-up marks the entry of Adani, India’s fastest-rising billionaire, into the three-way fight for domination of the onling shopping space, which is estimated to generate $200 billion in sales by 2026 -- turbocharged by pandemic restrictions keeping people away from stores.