Oil prices are down for the second straight session, after prices failed to sustain above $80 per barrel earlier in the week. Also have been weighed by data from API showing a rise in U.S. oil and gasoline inventories against an expectation of drawdown, while slowing global economy is likely to weigh on demand. In the session ahead, focus will be on the U.S. weekly oil inventory data from EIA and the beginning of pick summer driving season in U.S. next week.Technically, trend remains down till below 6600/ 6700, downside prices may test 6420-6350.