Wage increases escalated sharply in labor contracts negotiated during the first three months of the year, according to figures released yesterday by the Labor Department.

But the costly settlement between 160,000 mine workers and bituminous coal operators apparently skewed the figured sharply upward.

Increases averaged 9.9 percent for wages during the first year of agreements signed during January, February and March. During 1977, first-year wage increases averages 7.8 percent.

Total compensation - wages and fringe benefits - increased 14.6 percent during the first three months of 1978 compared with 9.6 percent in 1977.

Labor costs account for about 75 percent of the total cost of doing business in the United States, so wage and fringe benefit increases have an important effect on inflation.

To help slow down the rate of inflation President Carter has asked business and labor to co-operate with the government by reducing their wage and price demands by one-half of one percent this year.

Economists says that the underlying rate of inflation in the United States is between 6 and 7 percent, which represents the difference between the rise in total compensation and the increase in productivity (output per hour worked).

Although both wage increase in bargaining units of 1,000 workers or more and total compensation increases in units of 5,000 or more increased sharply during the first quarter, only a small number of workers was involved and most of the acceleration was due to the mine workers settlement.

Only 392,000 workers, in 76 different agreement, signed new settlements during the first quarter, and 160,000 of them were miners. During the second quarter, 370 major agreement covering 1.1 million workers are due to expire or permit re-opening of wage provisions, the Labor Department said.

Although first-year wage increases averaged 9.9 percent for all 392,000 workers signing new pacts in the first quarter, when the mine workers are factored out, the remaining 232,000 workers settled for wage increases of about 7.9 percent, roughly the same as the 7.8 percent level in 1977.

The Labor Department said it could not do the figuring because it cannot release specific contract terms. The calculations were done using Council on Wage and Price Stability estimates of the first-year costs of the coal pact.