Texaco Inc., the nation's second largest oil company, reported a modest 4.7 per cent earnings increase in 1976 over the previous year. It was the first big oil firm to post earnings for 1976.

Net income totaled $869.7 million ($3.20 a share) compared with $830.5 million ($3.06) in 1975. The company said revenues were approximately $26.93 billion up 7.3 per cent from $25.09 billion the year before.

For the fourth quarter, net income was $230.49 millions (85 cents a share), up 3.9 per cent from $221.94 million (82 cents) a year earlier. Revenues was about $7.33 billion against $6.42 billion.

Chairman Maurice F. Granville said 1976 earnings were adversely affected by a decrease in gross production of crude oil and natural gas liqiuds, and by increased U.S. income taxes.

Aluminum Co. of America, the world's largest aluminum porducer, announced strong fourth-quarter and full-year income gains in 1976 over the depressed levels of 1975.

Final-quarter net income was $39.6 million ($1.13 a share) versus $6.1 million (15 cents) the previous year. Sales and operating revenues rose from $566.9 million to $740.4 million.

For the year, net income was $143.8 million ($1.85) compared with $64.8 million ($1.85) in 1975. Sales and operating revenues advanced from $2.31 billion to $2.93 billion.

Aluminum shipments for the year rose from 1.34 million tons in 1975, to 1.64 million tons, the company said.

Westinghouse Electric Corp. earnings increased by 25 per cent in 1976 compared with the previous year, while sales went up by nearly 5 per cent.

Robert E. Kirby, chairman of the Pittsburgh-based firm, said net income for the year was $223.2 million ($2.54 a share) on sales of $6.1 billion. In 1975, earnings totaled $178.6 million ($2.04) on sales of $5.8 billion.

In the fourth quarter of 1976, Westinghouse earned $62 million (71 cents) on sales of $1.6 billion compared with income of $53 million (62 cents) on sales of $1.6 billion during the same period in 1975.

Kirby said all three operating companies, plus Westinghouse Broadcasting, showed sales and earnings improvements over 1975.

Allied Chemical Corp. says net income was higher for the final quarter but lower for the year because of a multi-million-dollar fine imposed in the Kepone case.

The company was fined $13.2 million last fall by a federal judge in Richmond for dumping kepone and other chemical-saturated process water into the James River. As a result, net income for the year was reduced to $112.1 million ($4.01 a share) against $116.2 million ($4.17) the year before.

Of the kepone fine, $600,000 was charged to fourth-quarter net income, bringing the figure to $36.4 million against $33.9 million in the final 1975 quarter. Earnings were $1.30 a share against $1.22 a year earlier.

Sales for the quarter were $655 million, up 6 per cent from a year earlier, while sales for the full year came to $2.62 billion, a 13 per cent increase from the $2.33 billion in 1975.

Southern Pacific Co. earned $4.10 a share in 1976, up 46 per cent from the $2.81 share earned in 1975. However, this was still below the record $4.20 a share earned by the big transportation combine in 1974.

But like a number of other companies Southern Pacific had a downturn in the final quarter, with profits dropping 12 per cent from a year earlier to $1.20 a share from $1.37 in 1975.

Net income for the year was $109.55 million on revenues of $1.883 billion compared with $74.93 million a year earlier on revenues of $1.647 a billion. Fourth-quarter net was $32.2 million on revenues of $485.83 million compared with $36.66 million a year earlier on revenues of $440.35 million.

Santa Fe Industries reported net income of $120.5 million with $109.2 million ($4.23) the previous year. Fourth-quarter net income was $35.1 million ($1.34) compared with $33.1 million ($1.28) for the corresponding 1975 period.Revenues for 1976 reached a record $1.594 billion, an 11 per cent increase over 1975 levels. Fourth-quarter revenues of $409.9 million were up 7 per cent from the 1975 period.

The company said its rail operation's contributions to pre-tax income declined to $47.5 million last year from $51.2 in 1975. The decline was attributed to higher maintenance costs, delays in obtaining freight rate increases to cover increased costs, and lower-than-expected traffic levels.

Sperry Rand Corp, reported a modest 4.8 per cent increase in earnings for the three months ended Dec. 31 over the comparable year-earlier period.

The manufacturer of computers from equipment and Remington consumer products, reporting for the third quarter of its fiscal year, said earnings advanced to $36.7 million ($1.05 a share) from $35 million ($1.01), a year before. Third-quarter revenues rose to $808.7 million from $778.7 million in 1975.