The chairman of the Maryland Public Service Commission said yesterday he is "looking into" the question of whether Maryland residents are subsidizing District residents by paying higher electric rates.

Thomas J. Hatem, chairman of the five-member body that regulates utility rates in Maryland, said he has asked the regulatory commission in the District for documents to aid in studying the question.

Suburban Maryland residents paid between 17 percent and 63 percent more than those in the District for the same quantities of electricity provided by Potomac Electric Power Co., according to statistics published in Sunday's Washington Post.

The statistics showed that Virginia residents in the Washington area paid between 6 and 60 percent more for electricity provided by the Virginia Electric and Power Co.

Reactions to the story varied.

"I have never understood a lot of the actions of the State Corporation Commission," said Virginia Del. Richard Saslaw (D-Fairfax), referring to the commission that regulates utility rates in the state. "It just seems that if there's a higher rate to be paid, northern Virginia is going to pay it."

A spokesman for the state corporation commission said that its chairman, Junie L. Bradshaw, was "a little loath" to discuss comparative costs at a time when the commission is considering Vepco's request for a $246 million, 25 percent rate increase.

Maryland Del. Charles S. Blumenthal (D-Prince George's) praised the District's Public Service Commission for holding down utility costs.

"The Public Service Commission of Maryland hasn't been doing as effective a job as the commission in the District of Columbia," Blumenthal said. "I'd like the (Maryland) commission to examine the efficiency (of utility companies) rather than just looking at arithmetic."

The chairman of the three-member District commission, Elizabeth Hayes Patterson, could not be reached for comment yesterday.

But another District commissioner, William R. Stratton, said that any subsidy to District Pepco customers by those in Maryland -- "if there is one" -- arises because the Maryland commission is more prompt in granting rate increases to utilities than is the case in the District.

Maryland People's Counsel Jack Keane, who represents customers in utility cases, said Pepco's Maryland customers are paying $10 million a year less -- on a prorated basis -- than District customers.

Keane declined to call this a subsidy, but said that if the commission would agree with his arguments in rate cases, "Then that would drop rates in Maryland."

Hatem said in a telephone interview yesterday that the statistics published in the Post were "the subject of some discussion we had this morning... We just asked for material from the District... to see if we can't look at (the two jurisdictions) together."