TRW, Inc., scientific and industrial combine, earned $4.77 a share in 1977, up from $4.02 in 1976, as sales soared to $3.264 billion from $2.929 billion. Net income was $154.2 million against $132.1 million the previous year.

Fourth-quarter profits were $43.6 million ($1.36 a share) on sales of $864.1 million compared with $36.2 million ($1.12) a year earlier on sales of $754.6 million.

Chairman Ruben F. Mettler said the trend to smaller automobiles components business because the company makes more components designed for small cars.

Jones & Laughlin Steel Corp., a subsidiary of LTV Corp., Tuesday reported a new loss of $2.98 million for 1977 compared with net income of $44.45 million for 1976.

J&L, the nation's seventh largest steel producer, said 1977 sales totaled $2.3 billion on shipments of 5.38 million tons compared with sales of $2 billion on shipments of 5.1 million tons in 1976.

The corporation reported a net loss of $3.87 million for the fourt quarter of 1977 on sales of more than $569 million. That compares with 1976 fourth-quarter net income of $9.98 million on sales of $475 million.

Increased foreign imports, rising costs, labor disruptions and bad weather caused the drop in performance for the steel marker and its parent company.

LTV lost $38.7 million last year compared with 1976 net income of $30.7 million ($2.34).

FMC Corp. net income and sales increased during 1977, the company said yesterday.

Last year's net income was $120.6 million ($3.33 a share diluted) compared with $80.2 million (2.22) in 1976.Revenues increased from $2.086 billion to $2.332 billion.

Fourth-quarter net income was $26.6 million (75 cents) on revenue of $689.3 million compared with 1976 fourth-quarter net income of $32.8 million (90 cents) on $530.2 million in revenues.

Discontinuing cellophane production during the current quarter created an $8 million charge against 1977 net income.

Sales of food and agricultural machinery and of chemicals were 9 per cent higher than in 1976; sales of airline, marine and rail equipment more than offset lower sales of petroluem and mining equipment, construction and power equipment sales were 10 percent higher; and government and municipal equipment sales rose by 11 percent.

Northrop Corp., a major manufacturer of military aircraft, yesterday reported record sales, net income and earnings per share for the fourth quarter and year ended Dec. 31, 1977.

Sales for the year were $1.6 billion, a 27 percent increase over the $1.26 billion recorded in 1976, with net income jumping 82 percent to $66.2 million from $36.3 million in 1976. Earnings per share for 1977 were $4.80, which was 67 percent above the $2.88 reported for 1976.

Sales, income and earnings for the fourth quarter were the highest of any quarter in Northrop's history. Sales were $451.8 million, up 29 percent over the $351.5 million recorded in the same period last year, with net income up 19 percent to $17.9 million from $15 million in the quarter ending Dec. 31, 1976. Fourth-quarter earnings per share of $1.28 were 17 percent more than the $1.09 registered a year ago.

Northrop Chairman Thomas V. Jones said improved results from the company's electronics, communications and construction businesses had contributed to the record 1977 earnings. Jones noted that 1976 income had been reduced by an after-tax charge arising from losses on investments.

Western Union Corp. net income last year was $45 million ($2.41 a share) compared with 1976 net income of $34 million ($2.10). Operating revenue rose to $650.5 million from $607.3 million in 1976.

Fourth-quarter net income of $10.4 million (53 cents) compared with $9.7 million (60 cents) in the 1976 fourth quarter. Operating revenue was $166.8 million in the latest quarter compared with $153.3 million a year earlier

Traditional telegram message service was the only part of Western Union's business that did not record increased revenue, and revenue from Mailgrams, an electronic mail service, was 25 percent higher than in 1976.