The first-degree murder charge accusing former Prince George's General Hospital nurse Jane F. Bolding of killing one of her patients last March was formally dropped yesterday.

During a brief hearing in Prince George's County District Court, Judge Irving H. Fisher dismissed the case for lack of prosecution. Last month the judge gave Prince George's State's Attorney Arthur A. Marshall 30 days to pull together his case against Bolding.

The 30 days expired on Saturday and Marshall said he and police still lacked sufficient evidence to take the case to trial and that he expected charges to be dropped automatically. Marshall refused to participate in yesterday's hearing, which he insisted was unnecessary.

Marshall said he expects it will take as much as a year to examine the records of 22 patients who died while under Bolding's care. He said that a pathologist from Walter Reed Army Hospital examined the records of five patients and determined that three, including Elinor Dickerson, 70, the patient Bolding was accused of killing, showed abnormally high levels of potassium.

Bolding was fired by the hospital when she was arrested and her attorney, Fred R. Joseph, is attempting to have her reinstated in her job in the intensive care unit.