OPEC boosts oil-demand outlook, yet group’s output increases In the U.S., crude stockpiles have dropped six straight weeks Oil retreated to the lowest level in more than two weeks after a surge above $50 a barrel didn’t last long. Futures slipped 2 percent in New York as support for the key $50 threshold proved weak. Even though U.S. crude inventories shrunk for a sixth week, the declines are seen by some investors as simply seasonal. While OPEC raised demand forecasts for its crude this year and next, a rise in Libyan production pushed the group’s output in July to the highest this year. “What you’re looking at is a nervous market,” Phil Flynn, senior market analyst at Price Futures Group Inc. in Chicago, said by telephone. “$50 is a major psychological number for this market and it may need to see a little bit more evidence of falling production […]