Two members of the Postal Rate Commission accused PRC Chairman A. Lee Fritscher yesterday of a "direct violation" of criminal conflict-of-interest rules.

His refusal to drop out of a case involving plans to speed large volumes of business mail electronically "establishes a clear disregard for the law," Vice Chairman James H. Duffy and commissioner Kieran O'Doherty charged in a hand-delivered memo to Congress.

Fritschler, a former acting dean at American University, had denied any impropriety. He did not return a reporter's phone call yesterday.

The conflict-of-interest issue arose from the 50-50 purchase of a $75,900 vacation apartment by Frischler and Joel Yohalem, a friend of 15 years who is Western Union's general solicitor and head of its regulatory division here.

Western Union and the U.S. Postal Service had reached an agreement on a joint, low-priced electronic message service (EMS). Under it, the company would flash messages from a single location to any of 25 post offices that would put them in envelopes and deliver them by hand. All parts of the nation would be served. At least in theory, the general public would benefit from a more efficient use of postal facilities and personnel.

The USPS asked the PRC to approve the proposal, called E-COM, in a 15-month proceeding.Half the hearing days involved the contract. Last Dec. 17, the five-member commission rejected E-COM, 3 to 2, while urging a substitute of its own that would use multiple carries and multiple points of entry for messages.

But the dissenters -- Duffy and O'Doherty -- and Rep. Edward J. Derwinski (ill.), senior Republican on the House Committee on Post Office and Civil Service, all charged that the PRC majority had gone beyond its Assigned advisory mission. They also charged that the substitute would leave the USPS powerless to control rates, relegate it to data-processing and "envelope stuffing" and fail to assure the entire country of access to EMS.

Last Friday, however, the presidentially appointed governors of the USPS voted unanimously to ask the PRC to take back the substitute and, in a new proceeding, consider purportedly "technical" changes. One such change would give the USPS something it very much wants: authority to compete with other carriers with an EMS of its own. The USPS would have to show an undefined "demonstrated need" for such a service.

Earlier last week, Duffy and O'Doherty protested that chairman Fritschler should have but hadn't told them of his condominium purchase with Yohalem. O'Doherty also said that the chairman should have stayed out of the first, 15-month proceeding. At the request of Derwinski, Chairman James M. Hanely (D-N.Y.) of the House committee ordered a staff investigation.

On Friday, Fritschler, without notifing Duffy and O'Doherty, sent each member of the House committee and its Senate counterpart a letter defending his conduct and praising the substitute plan.

The dissenters, learning of the letter, next asked Fritschler to disqualify or excuse himself from the second ECOM proceding, which already has begun.He refused.