The White House announced Wednesday night that President Trump is designating Neil Chatterjee as chairman of the Federal Regulatory Commission, replacing Kevin McIntyre, who is suffering from health issues.

Chatterjee, a Republican, does not need Senate approval to become chairman, since he is already a commissioner.

McIntyre, also a Republican and a Trump nominee, said that he intends to remain on FERC as a regular commissioner, but will relinquish his chairmanship.

"I will forever be grateful for the opportunity to serve as chairman and for the trust and confidence you placed in me to lead FERC at such a critical time in its history," McIntyre said in a letter addressed to Trump. "And I continue to be deeply grateful for the unwavering support and encouragement I have received from you, Mr. President, and from all other corners."

McIntyre was diagnosed with a brain tumor in the summer of 2017, and had recovered after treatment, allowing him fit to be FERC chairman. But he said he recently experienced a more serious health setback, leaving him "unable to perform the duties of chairman with the level of focus that the position demands and that FERC and the American people deserve."

Chatterjee, a former staffer for Senate Majority leader Mitch McConnell, R-Ky., previously served as FERC chairman on an interim basis before McIntyre was confirmed by the Senate last November.

Chatterjee has chaired the last two of FERC’s monthly meetings, which McIntyre has missed. He and fellow Democratic commissioners Cheryl LaFleur and Richard Glick offered prayers and best wishes for McIntyre at last week’s meeting.

“I am very sorry that Chairman Mcintyre is not able to be here today and continue to wish warm wishes for his recovery and I know that everyone here does,” LaFleur said.

FERC is already short one member after Republican commissioner Robert Powelson recently resigned. Trump has nominated Bernard McNamee, the head of the Energy Department’s Office of Policy, to fill the open seat.

The reshuffling comes as FERC has a busy agenda. It is currently deliberating over whether to change how power providers are compensated as the grid transitions away from coal and nuclear power, to more natural gas and renewables.

In a highly anticipated decision, FERC in January voted unanimously to reject a proposal from Energy Secretary Rick Perry to provide special payments to struggling coal and nuclear plants in the name of resilience and reliability, saying the grid faces no immediate risk without them.

McIntyre and Chatterjee both opposed the Perry plan. Chatterjee, who comes from the coal state of Kentucky like McConnell, expressed sympathy to the coal industry’s plight, but said providing subsidies would upset the balance of competitive wholesale electricity markets that reward the cheapest generation source.

FERC, in rejecting Perry’s plan, directed regional transmission operators to submit information on resilience challenges in their markets. The commission is reviewing those responses and could act on its own. Trump has repeatedly pressed for action to save coal and nuclear plants, but the White House has reportedly stalled over an effort to use emergency executive authority.

Any potential action would likely come through FERC, which is independent.

FERC is also currently reviewing its 1999 policy for approving pipeline projects, aiming to update it to reflect how to best manage the transport of bountiful shale natural gas to market, while balancing environmental and climate change concerns. And it is under pressure to more quickly approve liquified natural gas export projects to clear a backlog.