The Sensex at the Bombay Stock Exchange gained 199 points, or 1.2 percent, to close above the key 17,000 mark after more than three weeks, at 17,083, as investors bought blue-chips, amid rising European markets, today. The Nifty at the National Stock Exchange rose 54 points, or 1.1 percent, to 5,132.Stock markets in Japan, China, Hong Kong, Singapore, and South Korea ended mixed.