Walmart Inc.-owned homegrown e-commerce firm Flipkart is in preliminary talks with a clutch of new investors to raise at least $1 billion, even as it weighs an initial public offering (IPO) in the United States around the fourth quarter this year, at least four people in the know said. The fundraising could double to up to $2 billion—depending on investor appetite—and is largely for expansion, catalysing valuation ahead of the Flipkart IPO, as well as competing better with deep-pocketed rivals Amazon.com Inc. and Reliance Retail, the people said.