Nebraska regulators on Tuesday denied TransCanada Corp’s request to amend its route application for the proposed Keystone XL pipeline through the U.S. state, a potential setback for the company as it seeks to head off legal challenges. The Nebraska Public Service Commission (PSC) issued an approval for the line in late November, removing what appeared to be the last big regulatory obstacle for the long-delayed project, which has been backed by U.S. President Donald Trump. But the commission’s approval was not for the route TransCanada had singled out in its application. Instead, the commission approved an alternative route that shifts it closer to an existing pipeline right-of-way down the eastern side of the state, a move opponents of the pipeline have said violates state statutes. TransCanada filed a motion last month with the commission seeking permission to retrospectively amend the route application, […]