Cheryl LaFleur will lead the Federal Energy Regulatory Commission on an interim basis, the federal electric grid regulator announced Monday.

"I am honored to lead the commission at a time when the nation is making substantial changes in its energy supply and infrastructure to meet environmental challenges and improve reliability and security," LaFleur said.

LaFleur, a Democratic commissioner at FERC, replaces Jon Wellinghoff, who stepped down last week amid criticism for taking a job with Portland law firm Stoel Rives last month while still serving as chairman.

Wellinghoff's term had already expired at the end of June. But he had to stay on longer because Ron Binz, President Obama's first choice take over for Wellinghoff, pulled out of the confirmation process as Republicans threatened to block his nomination.