MUMBAI, April 16 -- Amazon.com Inc. is embarking on a massive India expansion plan, including a series of tie-ups with regional retail chains, to ensure that a legal setback in the case with Future Group does not upset its long-term plans for the country, two people familiar with the company's plans said.

"Even if Amazon loses the Future case, it's not fatal to Amazon by any means. The Future Group case is more about Amazon's emphasis that contractual obligations do matter in India," one of the two people said, adding that Amazon's organic investment plans are much larger than these investments.

Amazon's plans indicate that the US e-commerce giant will double down on its India investments and intensify pressure on rivals such as Walmart I...