Extending its gains for the sixth straight session, the Sensex at the Bombay Stock Exchange climbed 178 points, or 0.9 per cent, to close above the key 19,000 level after a gap of two months, at 19,121 on Tuesday. The Sensex rose on sustained buying by foreign funds, as falling crude oil prices further eased inflation and interest rate concerns. The Sensex has now added more than 1,280 points in just six trading sessions. The Nifty at the National Stock Exchange rose 49 points, or 0.9 percent, to 5,736.Stock markets in Japan, China, Hong Kong, South Korea and Singapore ended mixed.