Rising for the third straight session, the Sensex at the Bombay Stock Exchange ended with a small gain of 10 points, or 0.1 percent, at 19,179, amid positive European markets, today. The Sensex has now gained nearly 450 points in three trading sessions. The Nifty at the National Stock Exchange rose 3 points, to 5,837.But stock markets in Japan, China, Hong Kong, South Korea and Singapore declined between 0.3 percent and 2.6 percent.