Wholesale prices held steady in August, with a continued drop in food costs helping to offset rising energy prices, the government said yesterday.

Economists said the report would calm fears of renewed inflation.

The Labor Department's producer price index fell slightly from July, but the drop was insignificant after adjusting for seasonal variations.

The last time wholesale prices for finished goods did not increase was in November 1986.

"Some people would say that's no news, but no news on something like this is good news," said Dirk Van Dongen, president of the National Association of Wholesaler-Distributors. "To the extent that our cost of goods sold stays flat ... stability ripples through the system."

Similarly, White House spokesman Marlin Fitzwater said it was "good news and is in line with our forecast that the pickup in inflation during the first half of 1987 would prove temporary."

The unchanged prices in August dropped the annual rate of wholesale price inflation for the first eight months of 1987 to 3.6 percent, down from 4.2 percent for the first seven months.

Food prices fell 1.3 percent in August, continuing a decline of 0.6 percent in July and reversing sharp increases during the spring.

Inflation at the wholesale level was also held back by a 1.8 percent decline in new-car prices as manufacturers provided dealers with earlier than usual incentives to clear showrooms for the 1988 models.

Energy prices rose 1.5 percent in August, the same rate of increase as in July. Gasoline prices one step before the retail level climbed 4.2 percent. Putting aside the usually volatile food and energy categories, prices for a range of wholesale goods rose 0.3 percent in August, compared with a 0.2 percent increase in July.

"Excluding food and energy, inflation has been amazingly steady," said David Wyss, chief financial economist for Data Resources Inc., a forecasting firm in Lexington, Mass.

"We don't see much change in that trend," he said.

But Lawrence Chimerine, president of Wharton Economics in Philadelphia, cautioned, "Don't take today's numbers at face value. One of the big pressures on inflation is coming from import prices, and this doesn't show up directly in the PPI."