The head of Exxon Mobil’s massive exploration and production arm is retiring after more than three decades with the energy giant and will be replaced by a former General Motors executive.

Exxon Mobil said on Tuesday that Dan Ammann, former president of General Motors , will take over its largest and most profitable business early next year.

Spring-based Exxon Mobil Corp. (NYSE: XOM) has named two new presidents in the wake of a major retirement announcement. Liam Mallon, president of ExxonMobil Upstream Co. and vice president at Exxon, will retire Feb.

Exxon Mobil (NYSE:XOM) said Tuesday that Liam Mallon, the head of its E&P business, will retire effective February 1 after 34 years with the company, to be succeeded by Dan Ammann. Mallon has been president of Exxon Mobil Upstream (XOM) since 2022 after holding several leadership roles in Africa,