Rockwell International Corp. earnings for its first quarter of fiscal 1977 rose by 40 per cent from the same period last year.

The Pittsburgh-based industrial firm said earnings for the quarter ending Dec. 31, were $29.3 million (85 cents a share). Restated earnings for the same period in fiscal 1976 were $21 million (59 cents).

The restatement of year-ago results reflects the company's adoption of the Financial Accounting Standards Board statement on foreign currency translation. The change reduced previously reported first-quarter 1976 earnings by $3.1 million (11 cents).

Sales during the period were $1.3 billion, an increase of 13 per cent over sales of $1.1 billion a year ago.

Rockwell president Robert Anderson said the results reflected markedly improved earnings by the utility, industrial and aerospace operations.

Anderson also said the Admiral Group in the firm's consumer operations had higher losses, which he attributed to strong competition from abroad and to foreign currency translation losses.

Republic New York Corp., a bank holding company, said its operating net rose in the fourth quarter and full year. Net profits after securites transactions also were higher for both periods.

For the quarter, the company had operating gains of $4.21 million ($1.35 a share) against $4.11 million ($1.32) a year earlier. For the year, $16.5 million ($5.29) against $15.8 million ($5.08).

Consolidated net profit for the quarter came to $4.27 million ($1.37) against $4.17 million ($1.34) a year ago. For all of last year, the company made $16.5 million ($5.30) against $16 millon ($5.15) for 1975.

The company set aside $9.1 million for loan-losses for the year compared to $6.5 million the year before. Total loss reserve at the end of the year was $13.2 million, about 15 per cent of its net loans.

Continental Illinois Corp. yesterday reported record annual earnings for 1976 of $131 million as well as record-breaking earnings during the fourth quarter.

The annual earnings for the parent corporation of the Continental National Bank of Chicago represent $7.45 a share and a 10.1 per cent increase over 1975.

Fourth-quarter earnings were $35.2 million ($1.99 a share), a 17 per cent increase over the fourth quarter of 1975.

Chairman Roger E. Anderson attributed the record earnings to higher net interest income and increased fees and profits, as well as tighter control of expenses.

Continental Illinois reported loan charge-offs for 1976 as $72.7 million compared with $68.9 million in 1975. Loan loss provisions remained at last year's figure of $75 million.

Smithfield Foods, Inc., said preliminary data indicate 1976 profits of $1.54 million (59 cents a share) compared with $393,000 (16 cents) the previous year. Fourth-quarter profits were estimated at $1.05 million (40 cents) vs. $118,000 (5 cents). Sales for the year rose to $144 million from $138 million.

Joseph W. Luter III, president of the Smithfield, Va.-based firm, said the sharp increase was attributable to gains at Smithfield Packing Co., a major subsidiary. Luter also was elected chairman, effective last Monday.