Devon Energy Corp. (NYSE: DVN) was among explorers that plunged after the Interior Department ordered a 60-day moratorium on issuing drilling permits or oil and natural gas leases on federal lands. Devon slumped as much as 12% but finally closed 7,91% lower at $18,39. The Western Energy Alliance, which represents oil producers, said it’s prepared to challenge the ban in court. “We are prepared to challenge that temporary ban as a precursor to a longer term ban at the appropriate time,” said Kathleen Sgamma, who heads up the group.