The Sensex at the Bombay Stock Exchange rose 72 points, or 0.4 percent, to 18,151 in early trade, today. But the Sensex soon gave up all its initial gains, to slip below the 18,000 level. The 30-share index later stood 111 points, or 0.6 percent in the negative zone, at 17,968, on profit-booking by investors, in afternoon deals, a short while ago.Other Asia markets in Japan, China, South Korea, Indonesia, Singapore, Taiwan and Hong Kong were trading mixed.