The Sensex at the Bombay Stock Exchange declined 84 points, to 17,067 in early trade, today, on sustained selling by funds and retail investors, triggered by some disappointing corporate earnings, and weak regional bourses.Later, selling pressure intensified, and the Sensex lost considerably more ground, to stand 303 points in negative territory, and slip below the 17,000 level, at 16,848 in aftenoon deals, a short while ago. The 30-share Sensex had lost almost 170 points in the last two trading sessions.Other Asian markets in Hong Kong, Singapore, South Korea and Indonesia were down by between 0.2 percent and 0.6 percent, today. Across on Wall Street, the Dow Jones Industrial Average had lost 0.5 per cent in yesterday's trade, on weak economic data.