In the latest twist in the debate over the future of Girard College, the Board of Directors of City Trusts said Thursday that it would appeal an Orphans' Court decision barring the school from suspending its high school and boarding programs to save money.

At the same time, the board pledged to operate the secondary program for four more years to ensure current eighth graders can graduate from the school in 2018-19.

"Girard's financial challenges remain unresolved, and there is no doubt that they threaten the long-term survival of the school," board president Ronald R. Donatucci said in a statement. "For this reason, the board has concluded that it must appeal the Orphans' Court ruling to preserve the best chance to restructure the school's finances and position Girard for long-term survival."

The board filed a notice of appeal in Commonwealth Court on Thursday afternoon.

In July 2013, the board asked Orphans' Court for permission to amend Stephen Girard's will to suspend the secondary and residential programs in fall 2015. Without those changes, the board warned, the money to operate Girard could be depleted within 25 years and the school would be forced to close.

In August, Orphans' Court Judge Joseph D. O'Keefe ruled that Girard College could not suspend the high school and boarding programs to shore up its finances. The judge said those programs were critical components of the vision that the merchant-banker outlined in his 1831 bequest that created the free boarding school for poor orphans on a 43-acre site in Fairmount.

The board in September asked O'Keefe to reconsider. In its application, the board cited 18 instances in which it asserted he had erred. Last month, O'Keefe reaffirmed his ruling.

The school's decision roiled students, staff, and alumni.

"I wouldn't say I was surprised," said Joseph Samuel, president of the Girard College Alumni Association. "I was disappointed."

He said the association, which represents more than 3,000 Girard alums, thought O'Keefe's comprehensive opinion showed that he understood and respected Girard's educational vision.

Student body president Brandon Dixon, 17, a senior from Juniata Park, said students were enraged.

"Everybody is angry," he said. "It's irresponsible to make a decision this late in time."

Dixon said Girard president Clarence D. Armbrister told the school's seventh through 12th graders about the appeal at a 3 p.m. meeting in the high school auditorium.

Armbrister said the secondary program would continue to provide high school diplomas through 2018-19 no matter what happened in the courts.

"It took a moment to process that everybody sitting there would be OK - except the seventh graders," Dixon said. "You could see the anger building up in the room."

Dixon added: "We're going to continue to do our best to make sure that we all can graduate."

Girard's enrollment of 300 K-12 students includes 17 seventh graders.