A Northern Virginia company announced yesterday that it has called off plans to build a $400 million coal-burning power plant in western Anne Arundel County.

Ed Hall, project director for Applied Energy Services of Arlington, said the move resulted from the Potomac Electric Power Co.'s decision not to purchase the electricity that would have been generated by the 270-megawatt plant. When the project was announced in December, Pepco was seen as the plant's primary customer.

"Basically, they pulled the rug out from under us," said Steve Hase, the project's director, adding his company has already spent "a lot of money" on engineering and design plans.

Nancy Moses, a Pepco spokeswoman, said the utility's decision was entirely economic. Pepco believes that it can produce the electricity it needs more cheaply by building smaller, gas-generated plants that operate only at times of peak demand instead of the coal plant, which would operate year-round.

Applied Energy Services, after a six-month community relations blitz, had been receiving a relatively warm welcome from residents near the 20-acre site near the Baltimore-Washington Parkway where it planned to build the plant. The project was expected to bring 60 highly skilled jobs to Anne Arundel and hundreds more to Western Maryland's coal mines.