Waste Management Inc. appointed Steven Preston to the new position of executive vice president of finance, recycling & energy.

Preston had been president and chief executive officer of Oakleaf Global Holdings, which Waste Management acquired in July. Oakleaf provides outsourced waste and recycling services for large customers.

Preston will serve as the principal financial officer for Waste Management, assuming the duties of chief financial officer Robert S. Simpson, who retired Sept. 30. Preston also will also have management oversight responsibility for the company's recycling, waste-to-energy and organic growth business lines, the company said in a news release.

"Steve has a wide range of experience that will immediately add value at Waste Management," said David P. Steiner, company president and chief executive officer.

"Steve has previously served as the chief financial officer of a public company and held high positions in the George W. Bush administration, so he brings to WM strong financial management as well as operational leadership experience.”