Western Maryland residents outraged over high electricity bills from Potomac Edison Co. will be able to postpone paying half the fuel costs on their March bills for up to six months, the Maryland Public Service Commission ruled yesterday.

The order was a compromise between the demands of angry citizens, who urged that the "fuel adjustment" section of their bills be overhauled, and utility executives, who argued that high costs resulting from the nationwide coal strike had to be passed along to consumers.

"We've bought a little time, that's all," said Nancy Fost, the town clerk of Poolesville where Potomac Edison bills had their first impact. Fost's March bill for $794.61 included $450 for fuel costs in the two months that were covered. "At the end of the six months it's still going to be $450. Potomac Edison is still not absorbing any of the costs, nor are its stockholders," she said.

In an order that followed a two-day hearing, the three-member Public Service Commission directed Potomac Edison to offer its 55,000 Maryland customers a program allowing them to spread half the amount listed under "fuel adjustment" over the next six months.

On a typical bill of 10,000 kilowatt hours during the two-month period, the fuel adjustment cost would be $251.25, commissioner William A. Badger explained. The customer would have to pay only $125.63 immediately, with the rest paybale in whole or in part anytime before the end of September. Those who already paid their March bills can receive a refund check or a credit on future bills, he said.

Potomac Edison had proposed a different method of spreading a lesser amount of the bill over a four-month period. "The fact this does follow generally the method we proposed is good," said Potomac Edison president John M. McCardell. "At least the people who incurred the costs will pay them."

He was referring to arguments during the hearing from Maryland People's Counsel Jack Keane that the fuel adjustment rule should be revamped so as to spread costs equally over all consumers, regardless of whether they use more electricity in the summer or winter.

Keane said the ruling yesterday was "reasonable. They could have done more, but that part is reasonable. The dollars they deferred are probably as close an approximation as could be made to the actual amounts lost in the coal strike," he added.

Commissioner Badger, although he agreed to the final ruling, filed a dissent protesting the continuation of any fuel adjustment clause at all.

"Fuel now is the largest single cost of any utility," he said. "It's over half the bill in the case of Potomac Edison . . . we spend a great deal of time reviewing the 45 percent of the bill (that is in the basic rate charge) and it's time to take a closer look at the restof it."