Kevin McIntyre, who stepped down this week as chairman of the Federal Energy Regulatory Commission, will remain a member and preserve the panel’s 2-2 partisan split while the Senate considers President Donald Trump’s nominee to fill the vacant fifth seat.

Trump designated Neil Chatterjee to return to the role of chairman after McIntyre asked to be relieved due to health concerns.

McIntyre became chairman in December, after having surgery earlier last year to deal with a brain tumor. This summer he fell at a gym, damaging his spine.

“I very recently experienced a more serious health setback, leaving me currently unable to perform the duties of Chairman with the level of focus that the position demands and that FERC and the American people deserve,” McIntyre wrote in a Monday letter to Trump.

“I therefore propose to step aside from the position of Chairman and its additional duties so that I can commit myself fully to my work as Commissioner, while undergoing the treatment necessary to address my health issues,” he wrote.

McIntyre and Chatterjee are Republicans while Commissioners Cheryl LaFleur and Richard Glick are Democrats.

Trump earlier this month nominated Bernard McNamee, head of the Energy Department’s policy office, to fill the vacant seat on the commission. The Senate Energy and Natural Resources Committee has scheduled a confirmation hearing for McNamee on Nov. 15.

“I’m confident that Chairman Chatterjee will once again effectively lead the agency, and I will work with my Senate colleagues to restore a full complement of commissioners as quickly as possible,” said Energy and Natural Resources Chairwoman Lisa Murkowski, R-Alaska.

McIntyre was absent from FERC’s last two monthly meetings because of health concerns, leading to speculation he would step down as chairman.

“I have at all times endeavored to perform the extensive duties of chairman — above and beyond those duties shared by all commissioners — with full attention and vigor, despite facing some health challenges along the way,” McIntyre said in his letter to Trump.

Chatterjee, a former energy adviser to Senate Majority Leader Mitch McConnell, R-Ky., previously served as FERC chairman from August 2017 to December 2017, when McIntyre joined the agency.

“Although this is a difficult period for the Commission, I want to assure my fellow Commissioners, staff within the building and stakeholders outside it, that it’s my full intention to build upon Kevin’s hard work. But above all, I look forward to the day when my friend is back at full capacity,” Chatterjee said in a statement.

LaFleur said she looks forward to working with Chatterjee as chairman. “This is a time for close cooperation among everyone at the commission, and I will work as hard as I can to keep our work moving forward,” LaFleur said.

Glick noted FERC has a reputation as a nonpartisan agency. “In the coming weeks, let us reaffirm our commitment to consensus building and to maintaining the agency’s independence as we engage the nation’s energy business,” he said.

LaFleur and Glick have pushed for more extensive reviews of the impact of natural gas pipelines and liquefied natural gas facilities on greenhouse gas emissions and climate change. The lingering partisan division on the panel could delay pending pipeline and LNG applications at the agency.

Consulting firm ClearView Energy Partners said in a note to clients Thursday that a vote on McNamee could be paired next year with a replacement for LaFleur, whose four-year term ends June 30, 2019.

Pairing a Democratic nominee with a Republican could make it easier to move McNamee through a closely divided Senate, ClearView said.