NEW DELHI (Reuters) - Indian fintech firm Paytm has received approval from the capital markets regulator for its $2.2 billion stock market listing that is likely to be India’s biggest ever IPO, a source familiar with the matter told Reuters on Friday. Paytm was planning its initial public offering for around the end of October, Reuters previously reported. The company, whose backers include Ant Group, SoftBank’s Vision Fund and Berkshire Hathaway, narrowed its operating loss to 16.55 billion rupees ($221.00 million) in the financial year that ended in March 2021, from 24.68 billion a year earlier. A source told Reuters in July that Paytm was likely to break even in 18 months. Several first-generation homegrown startups in India are preparing to go public on domestic bourses, following on the heels of food delivery firm Zomato which made a stellar stock market debut in July and which also counts China’s Ant Group as a shareholder. Ant Group, with a roughly 30% stake, is Paytm’s largest shareholder. Launched a decade ago as a platform for mobile recharging, Paytm grew quickly after ride-hailing firm Uber listed it as a quick payment option. Its use swelled further in 2016 when a ban on high-value currency bank notes boosted digital payments. Paytm has since branched out into services including insurance and gold sales, movie and flight ticketing, and bank deposits and remittances. ($1 = 74.8880 Indian rupees) Reporting by Sankalp Phartiyal; editing by Jason Neely and Susan Fenton