BENGALURU, Sept 13 (Reuters) - Indian shares inched lower on Monday, dragged by heavyweight Reliance Industries after the conglomerate delayed the launch of a low-cost smartphone it is developing with Google, with investors awaiting key inflation data due later in the day. The blue-chip NSE Nifty 50 index was down 0.22% at 17,335.35 by 0348 GMT, while the benchmark S&P BSE Sensex fell 0.25% to 58,159.13. Billionaire Mukesh Ambani-owned Reliance Industries was the top percentage loser, down 1.3%, after its “ultra-affordable” smartphone — developed jointly by Reliance’s telecom arm and Google — was delayed to November. Investors are now looking to India’s retail inflation data that is expected to have held steady in August, as per a Reuters poll. In broader Asian markets, stocks traded slightly lower as key data this week from top economies United States and China were eyed by traders. (Reporting by Soumyajit Saha in Bengaluru; editing by Uttaresh.V)