AUGUSTA – An arbitrator has ruled in favor of a union representing Maine state workers in a case over service fees which nonmembers who receive union protection are required to pay.

Arbitrator Gary Altman sided with the Maine State Employees Association in a case brought by 35 workers who objected to the way the service fees are calculated.

The ruling comes two months after a federal judge rejected a larger challenge to the service or “fair share” fees.

The arbitrator’s ruling comes after an exhaustive process in which the objectors examined the MSEA’s financial documents. Both sides presented evidence and testimony, including cross-examination, during three days of arbitration hearings.

“The MSEA based its calculations with accurate and reliable financial data,” Altman wrote in a 42-page ruling dated May 4. He said the union spent money as shown in its financial statements and “met its burden of proof.”