By Nandita Bose MUMBAI (Reuters) – With Amazon.com Inc ramping up its presence in India, two local online retailers are preparing for tougher competition with separate deals worth a combined $400 million set to be finalized this week. Flipkart, Indias largest online retailer, is expected on Thursday to announce its acquisition of a majority stake in online fashion retailer Myntra in a deal worth about $300 million, said an official from Myntra who did not want to be named as he was not authorized to speak with the media. In a separate deal, local online retailer Snapdeal has raised $100 million from five investors, a company official said on Wednesday.