General Motors Corp. yesterday said 1976 net earnings were a record $2.9 billion, a 132 per cent gain over 1975 and the highest for any industrial corporation in 1976.

GM's record profits, dollar sales and earnings per share - topped by a record fourth-quarter performance - surpassed marks set in 1973.

Analysts expect even higher profits for the world's largest auto company this year.

GM chairman Thomas A. Murphy cautioned, however, that its profit reports were distorted by inflation and actually would be 6 per cent below 1973's level in constant dollars.

Murphy said the higher earnings during 1976 were principally accounted for by higher volume, changes in product mix and improved efficiency.

The world's largest auto maker also reported record sales of $47.2 billion, up 32 per cent from the previous high of $35.8 billion in 1973 and the $95.7 billion, set in 1973.

GM's 1976 profits, equal to $10.08 per share, compared with earnings of $1.25 billion ($4.32 a share) in 1975. The previous earnings record was $2.4 billion set in 1973.

The auto giant also posted record fourth-quarter earnings of $797 million ($2.77), up 29 per cent from $618 million, ($2.14) reported for the same 1975 period. The previous record for the quarter was $687 million set in 1972.

GM sales in the final quarter of the year were $13.1 billion, topping the record $12.5 billion reported for the second quarter of the year.

GM was the first of the automotive Big Three to report 1976 carnings.

Ford Motor Co. and Chrysler Corp. which also suffered sharp sales and profit setbacks during the recession, are expected to show record earnings on higher sales when they release their yearend results later this month.

Financial analysts say Ford could hit the $1 billion earnings mark - three times its 1975 net - for the first time in its history despite a four-week strike by the United Auto Workers last fall. And Chrysler, which lost a record $260 million in 1975, is expected to reveal earnings of about $400 million for 1976.

But small-car specialist American Motors Corp. remains in a sales and earnings slump. AMC earlier reported profits of $1.2 million for the fourth calendar quarter, which is the first quarter of its new fiscal year. Company officials have said the firm would not do much better than reach break even for the year.

Meanwhile, GM's board of directors declared a first-quarter dividend of 85 cents a share, payable March 10 to shareholders of record on Feb. 17. The company paid a record $5.55 a share in dividends last year.

Lockhead Aircraft Corp., yesterday reported that its net earnings dropped last year to $38.7 million from $45.3 million in 1975.

Lockheed, surrounded by controversy over questionable commissions to foreign officials and agents, reported debt of $450 million, including $100 million guaranteed by the U.S. government.

The company said sales for 1976 totaled $3.2 billion, a slight decrease from the $3.39 billion figure for the previous year.

Primary earnings per share of common stock for 1976 were $3.10 compared with $3.86 for 1975. On a fully diluted basis, per share earnings were $2.80 for 1976 compared with $3.49 the previous year.

The diluted earnings reflect, among other factors, the effect of warrants to purchase 1.75 million shares of common stock issued to lending banks on Oct. 27 in connection with the corporation's overall financial restructuring.

For the fourth quarter, Lockheed earned $7.4 million (50 cents a share), down from $7.9 million (68 cents) a year earlier.

In accordance with a change in L1011 TriStar accounting initiated in the fourth quarter of 1975, earnings for 1976 also reflect a full year's amortization of the commercial transport program's planning and tooling and production startup costs at the annual rate of $50 million.

Losses on the TriStar program during the year were $124.8 million compared with $93.8 million during 1975.

Lockheed said the company's independent public accountants would issue an opinion on the 1976 earnings, taking into account possible effects of disclosures of commissions and other payments by the company in connection with foreign sales.

Grumman Corp's 1976 earnings were up 15 per cent from 1975 despite lower fourth-quarter earnings, the corporation reported yesterday.

The year was a improvement for Grumman "mainly because of increased deliveries of profitable F-14 aircraft to the U.S. Navy and Iran," the company said.

Grumman's 1976 profits reached $27.2 million ($3.51 a share) from $23.5 million ($3.08) a year earlier. Revenues rose to $1.5 billion in 1976 from $1.4 billion in 1975.

However, fourth-quarter earnings fell to $5.5 million (71 cents) from $7.9 million ($1.03) the year before. Revenues also dipped to $408.9 million in the fourth quarter from $411.4 million in the comparable year earlier period.