By JOHN M. BRODER and CLIFFORD KRAUSS
A version of this article appeared in print on February 18, 2012, on page A15 of the New York edition
In a crucial step toward the ultimate approval of new oil drilling off the North Slope of Alaska, the Interior Department on Friday tentatively approved Shells plans for responding to a potential spill in the frigid Arctic waters.
Shell still needs to cross several more regulatory barriers before it will be permitted to begin drilling as many as six exploratory wells in the Chukchi Sea in July. But the green light from the Interior Department on the companys oil spill response plan is a clear sign that the Obama administration is disposed toward allowing the drilling despite the dogged opposition of many environmentalists.