Harford County Executive J. Thomas Barranger was indicted by a grand jury yesterday on charges of extortion and perjury, adding another major government official to the long list of Marylanders accused of political corruption.

Barranger, who was elected in 1978 to the top government position in the county north of Baltimore, allegedly extorted a $2.500 payment from an area hospital during his election campaign, according to the indictment.

In the past stormy decade of Maryland politics two Baltimore-area country executives were convicted on political corruption charges after investigations that also led to the resignation of former vice president Spiro Agnew. Agnew rose to national office from the posts of Baltimore County executive and governor of Maryland.

In the indictment handed up yesterday, Barranger was accused of extorting a payment from executives of the Fallston General Hospital, failing to report the $2,500 as income on his Maryland tax return and failing to turn the money over to his campaign treasurer.

Barranger told reporters he could not comment specifically on the specifically on the allegations, but said: "I have never engaged in any criminal conduct whatsoever . . . all I have ever done is to fight for this community."

Democrat Barranger defeated incumbent Charles B. Anderson Jr. in a bitter 1978 primary by promising a "new spirit" in government, an open and clean administration.

"He campaigned on a slate of 'Let's get the rascals out," said County Councilman Lehman Spry. "That's why this [indictment] is so ironic now."

Last year, Anderson was indicted -- and then acquitted -- on charges of fraud and misconduct in office.

In yesterday's indictment, Barranger was accused of extorting a $2,500 payment from two Fallston Hospital officials on Oct. 10, 1978, "by wrongful threat of economic injury."

The hospital had been involved in a lengthy tug-of-war with the county council and executive over a water tower that it hoped to build, according to Spry and other county officials.

The tower had been approved "in concept" by the council prior to Barranger's taking office, but funding for the tower had not been approved, according to Spry.

When Barranger and the new council officers took over, the tower again was approved in concept, but the funding was delayed while the officials awaited results of a "feasibility study" being done on the county's sewer needs, according to Spry.

The tower, according to Spry, still is being delayed by "citizen opposition and the feasibility study."

Barranger, discussing the grand jury investigation last month, denied that he had received any money from any hospital official.

"I think there may be people making those allegations, but they are absolutely untrue," he said. "The hospital has been under investigation for some time. If those people [hospital officials] are in trouble, maybe they're trying to turn something around. I've never done anything for them or to them."

The grand jury investigation, conducted by the office of Attorney General Stephen Sachs, led last year to the indictment of hospital finance director Alan R. Fialkow. He pleaded guilty to a charge of fraudulently misappropriating about $43,000 from the partnership that owns the hospital But in a statement filed in court, Fialkow alleged that his superiors had told him that some of the money would be used to take care of the hospital's political obligations.

Barranger said last month that he had talked to hospital officials during the campaign and told them his "position" on the water tower -- that it should be built with funds from a special tax on those who would benefit from its construction.

"I told them my position," Barranger said. "They thought it was okay. I'm probably a little naive about what's happening in the county. Maybe it was an error to meet with those people at all."

Hospital officials could not be reached for comment.