The workers are represented by the SEIU, Service Employees International Union, Local 32BJ, which has its headquarters in New York. Wayne MacManiman heads the Philadelphia office.
The Building Operators Labor Relations organization negotiates one contract on behalf of Center City building owners, operators, and cleaning companies. Most of the janitors are not employed by the building owners but work for various companies contracted to clean the buildings.
Robert G. Martin, BOLR's president, is also general manager of Brandywine Realty Trust, which owns the Cira Centre and One, Two, and Three Logan Square. Among other buildings that would be affected are the Comcast, Mellon, and Liberty Place towers.
Economic issues remain a sticking point. "The wage increases they are offering don't even meet inflation," MacManiman said. Workers are struggling to hang on to a middle-class lifestyle, he said.
Martin said that building owners are facing their own financial challenges.
"The real estate industry is dealing with a significant amount of vacancies in Philadelphia," he said. "Lease rates are down somewhat. We're dealing with extra taxes from Philadelphia - taxes increased 9 percent last year and will go up this year."
Contact staff writer Jane M. Von Bergen at 215-854-2769, jvonbergen@phillynews.com or @JaneVonBergen on Twitter.