Officials from the 40,000-student college wouldn't say whether 68-year-old Stephen Curtis resigned or was forced out.
Curtis declined to comment on his departure, set for September. An interim president will be named while the school searches for his replacement.
State and financial support has been declining at the college. Mayor Michael Nutter appointed himself and several aides to the board of trustees in October, in an effort to take a more active leadership role.
Curtis has drawn criticism as faculty and staff contract negotiations have dragged on for nearly two years. Union officials criticized his salary, which was then $286,000 including a housing and car allowance.