Philadelphia Energy Solutions, the giant South Philadelphia refinery complex that emerged from bankruptcy last week, has quietly installed fresh leadership under new owners.

Without fanfare, PES's new board of directors on Friday named Mark J. Smith, 59, as chief executive officer, replacing Gregory Gatta, who had been CEO since early 2017, before leading the company through bankruptcy this year.

Smith previously worked as president of refining and marketing at Western Refining Inc., which operated fuel-production plants in El Paso, Tex., Gallup, N.M., and St. Paul, Minn. before it merged in 2017 with a company now known as Andeavor.

PES, which operates the East Coast's largest oil refining complex in South Philadelphia, employs about 1,000 people.

The refinery was previously owned by Sunoco Inc., which formed a joint venture in 2012 with private-equity firm, the Carlyle Group. The joint venture declared bankruptcy in January, and completed the $635 million financial restructuring on Aug. 7.

The two largest creditors, Credit Suisse Asset Management and Halcyon Capital Management, how hold about 70 percent of the shares in the new company. Carlyle and Energy Transfer Partners LP, Sunoco's parent, have a combined 25 percent minority share.

The company, in a note to employees on Friday, said it planned to hold meetings with employees this week to introduce the new leadership and outline its business plan.

"The PES mission remains intact: To make the Philadelphia refining complex the most competitive supplier of refined petroleum products to the markets that we serve, while operating in a safe and environmentally responsible manner."