United States Steel Corp., the nation's largest steel producer, yesterday reported that 1976 profits fell by nearly $150 million to $410.3 million. Income for 1975 was $559.6 million.

Chairman Edgar Speer said the volume of sales for steel, industrial chemicals, agricultural chemicals and other products all increased in 1976. "However, the gains in income normally associated with this did not offset continuing increases in the costs of labor and purchased goods and services," Speer said. "And market conditions did not permit timely necessary cost-covering price increases," he added.

Sales were $8.7 billion in 1976 compared with $8.4 billion in 1975.

Steel shipments totaled 19.5 million tons last year, an increase of 2 million tons over 1975. Raw steel production reached 28.3 million tons, up from 26.4 million tons the previous year.

Fourth-quarter income was $80.5 million, compared with $111.6 million for the fourth quarter of 1975. Shipments of steel products for the quarter totaled 4.4 million net tons, up from 3.7 million net tons in the 1975 fourth quarter.

Capital expenditures for the year were $957 million and pollution abatement facility expenditures were about $90 million. For the last 10 years, such expenditures have totaled about $560 million, Speer said.

Company directors declared a dividend of 55 cents a share on common stock payable March 10 to stockholders of record Feb. 4.

Union Carbide Corp. earnings rose 15 per cent over 1975, including a hefty 30 per cent increase in the fourth quarter.

Fourth-quarter earnings reached $105 million ($1.69 a share) from $81million ($1.31) the year before. Revenues climbed to $1.63 billion from $1.43 billion a year earlier.

For the full year, the chemical company's earnings totaled $441 million ($7.15) against $382 million ($6.23) in 1975. Revenues were $6.35 billion in 1976 and $5.677 billion in 1975.

Kraft, Inc., yesterday posted record sales but reduced earnings from 1975 and sharply lower fourth-quarter earnings.

Worldwide sales totaled $4.98 billion, up 2.5 per cent but net earnings for the year were $135.6 million, a decrease of 2.8 per cent. Earnings per share were $4.86 compared with $5.01 in 1975.

Chairman William O. Beers said earnings before taxes were up 3.7 per cent. "Lower after-tax earnings for the year occurred because of international operations, fluctuations in foreign currency values and a resulting higher effective income tax rate," Beers said.

Fourth-quarter earnings were $30.4 million, a decrease of 30.1 per cent from the same period last year. Beers blamed lower international earnings and reduced margins on U.S. cheese sales, which were down.

Merrill Lynch & Co., parent of the country's largest securities brokerage house, yesterday said its revenues topped $1 billion for the first time in 1976.

Merrill Lynch had an 11.4 per cent gain in profits to $106.6 million ($3.01 a share from $95.7 million ($2.69) a year earlier. The rise in revenues was 14.9 per cent to $1.125 billion from $97.3 million in 1975.

Fourth-quarter revenues were up 23.4 per cent to $302.6 million from $241.3 million, and net income rose 16 per cent to $26.3 million (74 cents) from $22.7 million (64 cents) in the 1975 fourth quarter.

Chairman Donald T. Regan said commissions on trading in options and on trading in listed securities contributed a large part of the gain for the year. He also said Merrill Lynch Family Life Insurance Co. set records.

Weyerhaeuser Co., a lumber concern, has reported record 1976 fourth-quarter earnings of 65 cents a share compared with 28 cents in the final quarter last year. Earnings for the full year rose to $2.32 a share from $1.48 a share in 1975 for the second best 12-month performance in its history.

For th fourth quarter, net income rose 140 per cent to $85.7 million from $35.7 million a year earlier. Sales gained 18 per cent to $737.1 million from $622.6 million.

For the 12 months, the company earned $305.9 million, up from $188.8 million in 1975. Sales advanced 18 per cent to $2.868 billion from $2,421 billion.

President George H. Weyerhaeuser attributed the improved results to the recovery in the U.S. single-family housing market, the rebound in the Japanese housing industry, and strength in lumber, plywood and timber prices.