BENGALURU, Dec 12 (Reuters) - India's blue-chip Nifty 50 index opened marginally higher to hit a record high for the eighth session out of nine, ahead of a crucial inflation data and the U.S. Federal Reserve policy decision.

The NSE Nifty 50 index rose as much as 0.16% to a record high of 21,031.50 points, while the S&P BSE Sensex gained 0.12% to 70,010.58, as of 9:19 a.m. IST.

(Reporting by Bharath Rajeswaran in Bengaluru; Editing by Dhanya Ann Thoppil and Sonia Cheema)