The Sensex at the Bombay Stock Exchange rose 103 points, or 0.5 per cent, to 18,987 in opening trade, this morning, on fresh buying at lower levels, amid rising regional markets. Later, the Sensex gained further ground, climbing 143 points, or 0.8 percent, to regain the 19,000 level, at 19,027 in afternoon trade, a short while ago. The Sensex had lost over 680 points in the last four trading sessions.Stock markets in Japan, China, Hong Kong, Singapore, Taiwan and Indonesia had gained between 0.1 percent and 1.2 percent, today. The US the Dow Jones Industrial Average closed 0.4 per cent higher yesterday.