Crude oil dropped as the World Health Organization increased its global pandemic alert to the highest since the warning system was adopted in 2005, saying the disease is not containable. As per the survey of analysts, US crude supplies probably increased last week by 1.8 million barrels from their highest level since September 1990.

“From the oil market point of view, it’s the impact on travel and economic activity from swine flu that could affect prices,” said David Moore, a commodity strategist at Commonwealth Bank of Australia Ltd. in Sydney. “The market has been clanging around the high $40’s to the low $50’s for a while now and can’t get past the top side because the inventories are so high.”

Brent crude for June 2009 settlement fell as much as 95 cents, or 1.9%, to $49.37 a barrel on London’s ICE Futures Europe exchange. The contract fell $1.35, or 2.6%, to end April 27, 2009 session at $50.32 a barrel.