The corporation that owns the financially ailing Capitol Hill Hospital filed a formal notice of intent with city officials yesterday to change the general acute-care hospital to a specialty-care facility with inpatient and outpatient psychiatric and geriatric programs.

The planned change, which must be approved by the city's State Health Planning and Development Agency, would close one of the city's few emergency rooms and force the layoff of more than half the hospital's 600 employees.

Phillip Schneider, a spokesman for the nonprofit Medlantic Healthcare Group, which also operates Washington Hospital Center, said officials with the regulatory agency indicated a decision on the request might be made by the end of the year.

Schneider said the proposed changeover is necessary to keep the 102-year-old hospital operating as a health-care facility. This month, Medlantic officials said that they might be forced to close the hospital because of continuing financial losses, primarily from uncompensated patient care.

The hospital, at 700 Constitution Ave. NE, has 133 acute care beds and 30 skilled nursing beds, making it one of the city's smallest. But the hospital's location makes it the closest to the U.S. Capitol and congressional office buildings. Its location is also close to several major drug areas responsible for many of the patients who use Capitol Hill's emergency room.

Rick Ehrmann, vice president of Local 1199E-DC of the Service Employees International Union, said the proposed reconfiguration would be devastating to the hospital's work force, and said it would also place further strain on the overburdened D.C. General Hospital.

However, Schneider said Washington Hospital Center and other area hospitals would share in picking up the slack from Capitol Hill Hospital, which had an estimated 20,000 patient visits last year.

Because many of its patients are uninsured or underinsured, the hospital lost $4 million in fiscal 1990, and could lose as much as $6 million in the current fiscal year that began July 1, according to officials.

The proposed hospital restructuring would retain the 30 beds used for long-term intensive care. The plan also calls for adding 106 other beds that would be used for long-term nursing care.

After changeover, the hospital would employ about 250 people full time, Schneider said. Some employees will soon receive layoff notices.

Medlantic plans to hold a job fair at Capitol Hill Hospital next week to try to help place laid off workers with other Medlantic facilities. There are 300 openings in these facilities, Schneider said.