Snapping a three-day rising streak, the BSE benchmark index Sensex declined by nearly 52 points in early trade today as funds and retail investors preferred to book profits amid a weak trend in Asian markets. The 30-share index, which gained 140 points in the past three sessions, fell by 52 points, to 17,487 with stocks of IT, metal and realty sectors leading the fall.Similarly, the wide-based National Stock Exchange index Nifty declined by 15 points, to 5,312.