Deficit Hits $260.9 Billion in August; Record Is Seen : Government: With a month to go before the end of the 1991 fiscal year, the shortfall already eclipses the 1986 mark of $221.1 billion.

The federal budget deficit ballooned to $260.9 billion through August, the government said Monday, virtually ensuring a new fiscal-year record by the end of September.

“It fits with a yearly deficit of between $260 billion and $265 billion,” said economist Marilyn Schaja of Donaldson, Lufkin & Jenrette Securities Corp. in New York. If so, that would top the record of $221.1 billion set in 1986.

The Bush Administration projects a fiscal 1991 shortfall of $282.2 billion. It forecasts a $348.3-billion deficit for the fiscal year ending Sept. 30, 1992. The Congressional Budget Office contends that the shortfall will total $279 billion this year and $362 billion next.

The Treasury Department said the deficit rose $42.7 billion in August, 19.1% less than the shortfall in the same month of 1990.

For the year, however, the imbalance was 8.2% larger than the $241.2-billion shortfall in the first 11 months of last year.

Although the gap between spending and revenue after the first 11 months of 1990 topped the 1986 record, the shortfall dropped the next month to the point that the fiscal 1990 gap ended up at $220.4 billion.

Revenues through August of this year totaled $944.9 billion, up 1.8% from the same period of 1990. But spending jumped 3.1%, to $1.2 trillion, during the first 11 months of last year. For the month, revenues were at $76.4 billion, up 5.7% from August, 1990.

Receipts included $1.3 billion in contributions from allied nations to help pay for Gulf War expenses. So far this year, contributions have totaled $42.4 billion.

Expenditures amounted to $119.1 billion, 9.2% less than the same month last year.

Spending included $4.2 billion by the Resolution Trust Corp. for the thrift bailout.