The Bombay Stock Exchange benchmark Sensex declined by over 200 points in opening trade on Friday as funds and retail investors locked in gains recorded on Thursday's rally.The 30-share BSE index, which had gained 252 points in the previous session, fell by 202 points, or 1.21 per cent, to 16,495 in the first five minutes of trade on Friday.In a similar fashion, the wide-based National Stock Exchange Nifty index declined by 55 points, or 1.11 per cent, to 4,960.In the Asian region, Hong Kong's Hang Seng index was down by 1.28 per cent, while Japan's Nikkei index moved up by 0.25 per cent in early trade on Friday. The US Dow Jones Industrial Average ended 1.30 per cent higher on Thursday's session.