The D.C. government has balanced its operating budget for the fourth year in a row, using $17.5 million that was left over from 1984 spending to further reduce the city's accumulated deficit, according to an independent audit of the fiscal 1984 budget released yesterday.

The accumulated deficit, which totaled $377.8 million in 1981, today stands at $269.9 million, the new audit shows.

The District also appears to be putting the separate water and sewer fund on a steadier financial footing, primarily as a result of sharp increases in water service charges. However, the city must continue to pump large operating subsidies into the semi-autonomous Convention Center, D.C. General Hospital and the University of the District of Columbia.

"I see this as a positive trend," Mayor Marion Barry said yesterday in reviewing the audit's findings. "It does not mean we do not have problems with the deficit. We still have a major deficit problem. But every year, for the last four years, we have been able to significantly make a dent in it."

At a news conference, Barry also sought to assure officials of local hospitals, churches, universities and other nonprofit organizations that he does not intend to eliminate their exemptions from D.C. property taxes.

The D.C. Department of Finance and Revenue caused a furor early this month when, without warning, it published proposed changes in tax regulations that many feared would result in the wholesale elimination of tax exemptions for non-profit groups.

Officials of some of those organizations also complained that the city had given them only 10 days in which to respond before the rules were to go into effect, instead of the usual 30 days. Since then, the city has granted an additional month for public comment and review.

"I think when finally the dust has settled, you'll find that there's no danger to churches that are used for church purposes and educational institutions used for educational purposes. . . of losing their property tax exemptions," the mayor said.

"We do have to be careful and make sure, though, that just because you call yourself an education center that education is going on there," he added.

In the fiscal year that ended Sept. 30, the District had revenues totaling approximately $2.403 billion and expenditures and other uses totaling approximately $2.385 billion, leaving $17.4 million in "excess," according to the audit.

Of the expenditures, nearly 34 percent went for human support services, 26 percent for public safety and justice, about 20 percent for education, 10 percent for public works and about 7 percent for interest payments.

Property tax revenues came in slightly below city projections, while sales and use taxes, income-franchise taxes and gross receipts taxes came in slightly above projections, according to the audit.

The D.C. Lottery raised $25.2 million in revenue for the general fund in 1984 -- about twice the amount raised the previous year, but still about $15 million below the projection.

The mayor took credit for the city's success in whittling down the accumulated deficit. However, on several occasions it was the D.C. City Council or Congress, not Barry's administration, that insisted funds be set aside for deficit retirement.

During the past four years, the city has reduced the general fund deficit by a total of $107.9 million to the current level of $269.9 million.

A separate issue has been the city's less successful efforts to do something about the water and sewer system, the Convention Center, D.C. General and UDC, which have all operated in the red and required major subsidies.

The city council approved a series of increases in water charges over a five-year period designed to put the water and sewer system on a pay-as-you-go footing. However, the other semi-independent facilities indefinitely will continue to rely on major operating subsidies from the general fund.

The city provided a total of $85.6 million in subsidies to those facilities in fiscal 1984, according to the audit, or about $6 million less than was provided in 1983.