More than 800 workers at Newark Liberty International Airport are facing layoffs after United Airlines changed contractors, but the employees will be given a chance to re-apply for similar jobs.

United Ground Express, a subsidiary of United Airlines, will begin handling many of the wheelchair, security and passenger services that vendor ABM Aviation currently provides, United Airlines said in a statement.

United Airlines' contract with ABM was due to expire and sent out to bid, the airline said. United is the largest carrier at Newark Liberty International Airport.

United Group Express was awarded about two-thirds of the existing work and will begin recruiting for the open positions. Omni-Serv will take over some mail room support, door monitoring, inter-terminal bus transfers and bag room work. ABM will continue to provide skycap services, United said.

The Worker Adjustment and Retraining Notification notice issued by the state department of Labor and Workforce Development says 821 employees of ABM Aviation will be laid off on or before Nov. 1.

The WARN notice is a required 60-day notification that must be provided when mass layoffs are planned.

"All impacted employees have the opportunity to interview for other roles within ABM, and we are working closely with them for placement opportunities," an ABM spokeswoman said in an emailed statement.

ABM Aviation supplies 15,000 employees to airlines and airports across the country.

The Newark Airport workers were expected to get a living wage of $19 an hour from the Port Authority of New York and New Jersey in about two weeks, according to Hector Figueroa, President of 32BJ SEIU which represents the employees.

"No, just two weeks before Newark Airport workers are poised to win a living wage of $19 an hour from the Port Authority of New York and New Jersey, United is undermining the progress they fought so hard to win," Figueroa said. "This is an unacceptable effort to undermine worker's democracy and keep them from claiming the Union representation they voted for."

Port Authority of New York and New Jersey Commissioner Kevin O'Toole said he was "extremely disappointed" about the layoffs and was not given "prior consultation."

"Given the longstanding business relationship with United and our mutual commitment to open communication and close collaboration, we were extremely disappointed to hear of United's plans for this significant change in service providers with prior consultation or involvement," O'Toole said in a statement. "This was worsened by the timing of the United's announcement in midst of the Board's ongoing consideration of an increase to the minimum wage for airport workers leading to speculation about their motives for the change."

He said the airport has requested background information on the subcontractors United plans to use.

Jeff Goldman may be reached at jeff_goldman@njadvancemedia.com. Follow him on Twitter @JeffSGoldman. Find NJ.com on Facebook.