Crude slips to six-month low US crude oil fell to a six-month low as strong domestic production pushed inventories to the highest level in decades. Nymex June West Texas Intermediate, the US benchmark, fell 86 cents to $93.12 a barrel after dipping to $91.81, the weakest since November. ICE June Brent, which expired on Wednesday, slid 64 cents to $111.60 a barrel. Oil's weakness was exacerbated by renewed worries about the global economy amid questions about Greece's membership in the eurozone. In the US, the Department of Energy reported that commercial crude stocks rose by 2.1m barrels last week to 381.6m barrels, the most since 1990. Stocks at Cushing, Oklahoma, the delivery point for Nymex crude futures, climbed 1m barrels to a record 45.1m barrels. Surging production in the central US and Canada has swelled oil inventories at landlocked Cushing, which have in turn helped to discount the price of WTI to the North Sea's Brent and other important crude streams. This week's planned reversal of the the Seaway pipeline will deliver 150,000 barrels a day from Cushing to the Gulf of Mexico market, where they will compete with imported barrels. But analysts said Seaway's current capacity will not be enough to alleviate the glut. The pipeline's owners, Enbridge and Enterprise Products Partners, plan to increase its flow to 400,000b/d next year while the TransCanada pipeline company hopes to build a separate line from Cushing to the Gulf carrying more than 700,000b/d. "The problem is that the volume going though Seaway is not adequate to relieve the significant pressure in Cushing," said Ed Morse, head of commodities research at Citigroup. He pointed out that last week's rise in Cushing stocks amounted to 143,000b/d - almost the entire capacity of Seaway. Both WTI and Brent prices have fallen as economic worries take hold in Europe. Brent prices are higher partly because of output cuts from Nigeria, a key supplier of similar light, sweet crude in the Atlantic ocean marketplace, said Andy Lipow, a Houston consultant. JPMorgan Chase, in a note, said that crude demand from Asian refineries was expected to rebound as they finish seasonal maintenance projects, potentially drawing down stocks around the Atlantic. The bank added that "in contrast to the weakness in US domestic crude grades, the broader physical market seems to be on a tightening path," potentially boosting oil prices later in the year.