Marathon Oil Corp. announced Thursday that its long time chief executive, Clarence Cazalot Jr., will retire this year and will be replaced by Exxon Mobil Corp. executive Lee Tillman.
Mr. Tillman, who helped manage projects around the world for the Exxon Mobil, will take the reins at Marathon on Aug. 1 when Mr. Cazalot steps down.
Mr. Cazalot has served as Marathon's chief executive for nearly 14 years and is approaching the company's mandated retirement age of 65 years old for executives. He will remain chairman of the company's board through the end of the year.
Mr. Cazalot saw Marathon through major changes--the company separated from what became United States Steel Corporation and became a standalone under his leadership in 2002.
More recently, Mr. Cazalot oversaw Marathon's transition from an integrated oil company that was heavily focused on its international operations to an independent exploration and production company that has seen its production boosted by its focus on U.S. shale oil formations such as the Eagle Ford and the Bakken.
Marathon was one of the first exploration and production companies of its class to take notice of the promise of so-called tight oil from shale fields, which, due to hydraulic fracturing techniques first applied in natural gas fields, have led a resurgence in U.S. oil production.
But Raymond James analyst Pavel Molchanov said picking its new leader from the ranks of the world's largest integrated oil company is a sign that Marathon has no plans to abandon its global business model.
"Their current growth is more focused on domestic and unconventional formations than it historically has been, but this hire suggests that there is definitely a remaining culture within the company that is open to international opportunities and large projects," Mr. Molchanov said. "Mr. Tillman's global footprint in many ways matches Marathon's."
Mr. Tillman, 51 years old, most recently was vice president of engineering for ExxonMobil Development Co., has spent his career at Exxon and has worked in Jakarta, Indonesia; Aberdeen, Scotland; Stavanger, Norway; Malabo, Equatorial Guinea; Dallas and New Orleans.
Dave Roberts, Marathon's former chief operating officer, had widely been seen as a possible successor for Mr. Cazalot, but abruptly left the company late last year.
Marathon Oil was up 1.5% at $33.88 in Thursday trading. The stock is up 10% this year.