(Adds details of objections to Bay, background on LaFleur, other details)
By Ros Krasny
WASHINGTON, June 18 (Reuters) - The U.S. Senate Energy Committee voted on Wednesday to advance the nominations of Norman Bay to be a commissioner of the Federal Energy Regulatory Commission and Cheryl LaFleur for a second term as commissioner at the utility agency.
After a contentious hearing, Bay's nomination was approved by a 13-9 vote. The nomination of LaFleur, currently the acting chair, advanced by a 21-1 vote.
President Barack Obama has said he intends to elevate Bay, who joined FERC in 2009 as head of its enforcement division, to chairman once he is confirmed by the Senate.
Most Republicans voted against Bay, taking their lead from Alaska's Lisa Murkowski, her party's senior member on the panel.
It is unclear when the full Senate will consider the nominations for FERC, which regulates elements of the U.S. natural gas, electricity, oil and hydropower industries, including the reliability of the electricity grid.
Bay is a former federal prosecutor and law professor at the University of New Mexico. At FERC, he has led investigations into energy trading practices at major Wall Street banks.
Murkowski has pushed hard for LaFleur, with a deep background in utility regulation, to be named to the top job at FERC, which she has held on an acting basis since November.
Bay "is clearly a learned man, but does he have the experience in the energy policy and regulatory policy that FERC deals with on a day-to-day basis? I haven't been convinced," Murkowski said. I'm not interested in someone in charge of FERC doing on-the-job training,"
Senator Joe Manchin, Democrat of West Virginia, said he understood the White House would retain LaFleur as acting chair for nine months before Bay took over.
But Murkowski said she had not received that assurance from the administration.
LaFleur was first nominated to FERC by Obama in 2010 after two decades in the electric and natural gas industries, including a spell as acting chief executive of National Grid USA. Her FERC term expires this month.
The agency has been without a permanent head since Jon Wellinghoff departed in November.
Obama's first choice as replacement, Colorado regulator Ron Binz, withdrew from consideration in October after it became clear his nomination was unlikely to clear the energy panel.
Binz was criticized by some conservative groups as favoring renewable energy sources like wind over coal and natural gas.
(Reporting by Ros Krasny; Editing by Susan Heavey and Peter Cooney)