Two former employes of the National Rural Electric Cooperative Association and an acquaintance were charged yesterday with defrauding the group of approximately $170,000.

Assistant U.S. Attorney William D. Pease of the fraud division filed the charges in U.S. District Court here against Theresa J. Enfield, 28, of 3307 Nicholson St., Hyattsville; Katalina Kulifay-Nagy, 29, of 1813 N. Veitch St., Arlington; and James Michael Grier, described as being in his late 20s, who is an airman stationed at Shaw Air Force Base, Sumter, S.C.

Enfield and Kulifay-Nagy had worked at NRECA in the retirement and savings department until earlier this summer. They submitted their resignations shortly before NRECA began an internal investigation into accounts the two were handling, officials said.

According to investigators, the two women would create fake names and have lump sum retirement and savings checks made payable from member firms of the electric cooperative to those fake names. They would then call and tell the member companies they had made a mistake, and ask the companies to mail the checks back to them privately so their supervisors would not know about the mistake, investigators allege.

The criminal charges claim that the women and Grier would cash the checks instead of destroying them when they were mailed back. The investigation is continuing, Pease said.

Investigators allege the defendants had cashed at least $103,000 of the checks before being caught and had spent the money on items such as personal trips. They are specifically charged with mail fraud and interstate transportation of money obtained by fraud.