David Steiner, a former CEO of the nation's largest waste management company who currently serves on the FedEx board of directors, is poised to take over control of the U.S. Postal Service, becoming the nation's 76th postmaster general.

The announcement of Steiner's appointment, which drew immediate 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.

"We anticipate that Mr. Steiner will join the organization in July, assuming his successful completion of the ethics and security clearance processes that are currently underway," McReynolds said.

Friday's announcement by the the Board of Governors comes as President Donald Trump and his adviser Elon Musk's Department of Government Efficiency have raised the idea of privatizing the nearly 250-year-old Postal Service, which has faced financial challenges amid a changing mail mix and other issues.

The choice of Steiner has been seen by the postal unions as a harbinger for possible privatization of some or all of the venerable quasi-public institution, which is largely self-funded and has a mission to serve every address in the country -- nearly 167 million residences, businesses and post office boxes.

Postal unions have held protests throughout the country over potential privatization, job cuts and possibly ending the universal service obligation.

Brian L. Renfroe, president of the National Association of Letter Carriers, said Steiner is not just any executive from the private sector but someone who sits on the board of one of the Postal Service's top competitors.

"His selection isn't just a conflict of interest -- it's an aggressive step toward handing America's mail system over to corporate interests," Renfroe said in a statement. "Private shippers have been waiting to get USPS out of parcel delivery for years. Steiner's selection is an open invitation to do just that."

Renfroe's union represents 205,000 active city letter carriers and around 90,000 retirees.

Mark Dimondstein, president of the American Postal Workers Union, which represents more than 220,000 USPS employees and retirees, likened the appointment of Steiner to a fox guarding a hen house.

"FedEx has a very different agenda than the public postal service. And they're a major competitor of the United States Postal Service," he said. "I'm not talking about any attributes of an individual, but to me, that's the last type of person you will put in charge of the public institution as the anchor of the mailing package industry in the country."

Steiner, who will leave the FedEx board, said in a written statement that he admires the public service mission of the USPS and called it "an incredible honor to be asked to lead the world's greatest postal organization."

"I believe strongly in maintaining its role as an independent establishment of the executive branch," said Steiner, who served as CEO of Waste Management Inc. from 2004 through October 2016.

In a written statement, McReynolds called Steiner "the right person to lead the Postal Service at this time to ensure this magnificent and historic organization thrives into the future."

"Dave is a highly regarded leader and executive with tremendous vision, experience and skill that can be applied to the long-term mission and business needs of the Postal Service," she added. "Our Board looks forward to working with Dave as he takes on the core mandates of providing universal and excellent service for the American public and doing so in a financially sustainable manner."

The Postal Service is in the midst of a 10-year modernization and cost-cutting plan that began in 2021 under Postmaster Louis DeJoy, who resigned in March. The plan is an attempt to stop losses at the agency, which has a budget of about $78 billion a year and is mostly self-funded, including through stamps and packages.

Known as "Deliver for America," the initiative has received markedly mixed reviews. While postal officials contend it has led to major efficiency improvements, some members of Congress have criticized it for leading to mail delays, unsustainable postage increases and declines in business.

Besides privatization, there's also been talk of possibly moving the USPS under the control of the U.S. Department of Commerce.

The choice of Steiner was first reported by The Washington Post.