BERLIN (AP) — The CEO of energy company Uniper has decided to step down after the German government nationalized the gas supplier last month, Uniper said Tuesday.

Klaus-Dieter Maubach is exercising a special right to terminate his contract and will leave the board this year, Uniper said in a statement. It added that Maubach, who has led the company since March 2021, was willing to stay in the job until a suitable replacement is appointed.

The German government announced its plan to nationalize Uniper in September, expanding state intervention in the energy sector to prevent a shortage resulting from Russia’s war in Ukraine. The deal built on an initial rescue package agreed in July and featured a capital increase of 8 billion euros ($8.5 billion) that Germany financed.

Shortly before Christmas, the government took a stake of some 99% in the company. Uniper's existing management remained in place.

Maubach said in Tuesday's statement that the nationalization “marks the start of a new phase.”

“A strategic realignment of the company will have to take place, and there is no time to lose,” he said. "I am convinced that now is the right time to clear the way for a new Management Board team to take on the new challenges beyond the end of the stabilization measures.”

Under the terms of the European Commission's approval for Uniper's nationalization, the German government must reduce its stake to 25% plus one share by 2028. The deadline can only be extended with the commission’s approval.

Uniper said its chief operating officer, David Bryson, also plans to step down.

Before the invasion of Ukraine, the company bought about half of its gas from Russia, which started cutting deliveries to Germany in June and hasn’t supplied any gas to the country since the end of August.

Uniper has incurred huge costs as a result of those cuts because it was forced to buy gas at far higher market prices to meet its supply contract obligations.