The Sensex at the Bombay Stock Exchange declined 57 points, or 0.3 per cent, to 19,419 in opening trade, this morning, as investors booked profits after two sessions of gains, amid subdued Asian bourses. Later, the Sensex remained weak and stood 88 points, or 0.5 percent in negative territory, at 19,388 in afternoon deals, a short while ago. The Sensex had advanced over 230 points in the previous two trading sessions.Other Asian markets in Japan, China, Hong Kong, Indonesia and Taiwan were down by between 0.3 percent and 1.3 percnt, today, as doubt set in over the progress of US budget talks.