Pittsburgh-based UPMC said it has entered into an integration and affiliation agreement with Washington (Pa.) Health System, according to an Oct. 23 filing.

The two signed a letter of intent in June regarding the partnership. Unions have criticized the move, saying it would harm both patients and workers.

UPMC will appoint about one-third of the Washington Health board directors and the system will be renamed UPMC Washington, according to the filing.

The proposed transaction still has to meet regulatory and closing conditions.