West Texas Intermediate crude’s discount to Brent narrowed the most in a week after Morgan Stanley said stockpiles at Cushing, Oklahoma , are weeks away from reaching minimum levels. The U.S. grade settled above $99, and Brent slid 0.6 percent. Supplies at Cushing, the delivery point for New York-traded futures, may reach a floor of around 20 million barrels in two to three weeks, Adam Longson, a Morgan Stanley analyst in New York, said in an e-mailed note yesterday. Brent dropped as two oil fields in western Libya are scheduled to resume production this week. “Historically, the minimum operating inventory level has been in the neighborhood of 20 million barrels, and we are approaching the minimum,” James Williams, an economist at WTRG Economics, an energy-research firm in London , Arkansas , said by phone. “It’s supportive for front-month WTI. It would have a tendency to narrow the price differential […]