PORTLAND — The state’s largest hospital said Friday that it expects to finish the fiscal year with a $500,000 budget deficit — the first such shortfall in more than a decade.

Although the loss will be covered by donations and interest accrued from endowments, this is the first time in at least 15 years that revenues will not cover operating costs at Maine Medical Center.

Hospital officials also predict a $1 million deficit at MMC in 1991.

News of the projected shortfalls comes a week after hospital president William Deal resigned.

Interim president, Donald L. McDowell, said the hospital’s budgetary problems were unrelated to Deal’s departure.

MMC’s operating budget was $171 million this year and is expected to top $185 million for fiscal year 1991, which begins Oct. 1. The hospital employs 2,900 full-time workers, McDowell said.

The hospital plans to increase its rates between 5 and 10 percent this year to cover rising operating costs, McDowell said.