https://www.reuters.com/article/us-facebook-reliance-jio/facebook-to-buy-10-stake-in-telco-unit-of-indias-reliance-industries-for-5-7-billion-idUSKCN22404I >Facebook will buy a 10% stake in the digital business of India's Reliance Industries for $5.7 billion, as the social media firm looks to leverage its highly popular WhatsApp chat service to offer digital payment services.