Environmental Protection Agency administrator Gina McCarthy, pictured here looking at Alaska's Portage Glacier, will play a critical role in determining if Alaska's Pebble Mine project moves forward. (Credit: EPA) Environmental Protection Agency administrator Gina McCarthy, pictured here looking at Alaska's Portage Glacier, will play a critical role in determining if Alaska's Pebble Mine project moves forward. (EPA)

Anglo American, the London-based  company which owned a 50 percent share in the Pebble Mine project slated for Alaska's Bristol Bay watershed, announced Monday it was pulling out of the venture.

While Pebble Mine's original backer, Northern Dynasty Minerals, plans to proceed anyway, the move could hamper a controversial proposed copper and gold mine that has become a lightening rod for environmentalists, fishing interests and several native Alaskan tribes.