Falling for the fourth straight session, the Sensex at the Bombay Stock Exchange dropped 157 points, or 0.8 percent, to 19,292 on Thursday, on concerns about high oil prices and food inflation. The Nifty at the National Stock Exchange shed 48 points, or 0.8 percent, to 5,785. Stock markets in Japan, China, Hong Kong, South Korea and Singapore again ended mixed, even as the US central bank decided to keep interest rates steady.