NEW CASTLE — The stalled merger between Jameson Health System and UPMC was unstuck Thursday by an independent arbitrator who ruled the proposed deal can go forward, the hospital said.

In his ruling, former Chief Judge Donald Ziegler gave the two hospital systems permission to move forward with the merger, which is valued at $80 million.

The merger was opposed by the Pennsylvania Office of Attorney General amid antitrust concerns.

Jameson spokesman Lisa Lombardo said Ziegler ruled that a rebidding effort by the hospital at the behest of the AG’s office “did not produce a ‘Qualified Bid’ ... which meets the qualifying criteria for serving the long-term interests of the residents of Lawrence County.”

Jameson and UPMC had announced a deal to merge in September 2014, but the state AG’s office rejected the idea, saying the resulting health system would control more than 70 percent of the region’s inpatient services, and could result in less competition and higher costs to patients.

The AG’s office told Jameson to seek other offers, and in October 2015 the hospital said it had received three bids from other potential partners — including one from Butler Health System — but called them “insufficient.”

The AG’s office disagreed, and the matter went before Ziegler earlier this month.

As a result of Ziegler’s ruling, Lombardo said, the AG’s office has agreed to drop its opposition to a Jameson-UPMC merger, but Jameson must still negotiate with UPMC to address antitrust concerns.

“There is still work to do until the deal is final,” Lombardo said.

Lombardo said a merger proposal addressing those concerns is already in the hands of the AG’s office, and that Jameson “looks forward to the timely completion of this process ...”