A former CEO of the nation’s largest waste management company who currently serves on the FedEx board of directors will take over control of the U.S. Postal Service.

The announcement of Steiner’s appointment, which heightened concerns from postal unions over possible efforts to privatize the USPS, was made Friday by Amber McReynolds, chairperson of the USPS’ Board of Governors, during a meeting of the independent group that oversees the service.