Posting its third straight day of losses, the Sensex at the Bombay Stock Exchange declined 142 points, or 0.7 percent, to 19,318, today, on heavy selling especially in realty stocks, after sentiment was hurt by the home loan racket. The Nifty at the National Stock Exchange shed 66 points, or 1.1 percent, to 5,800. But stock markets in Japan, China, Hong Kong, Singapore and South orea rose between 0.1 percent and 1.3 percent.