Continental Oil Corp., the nation's ninth largest petroleum firm, earned $460 million ($4.38 a share) in 1976, up from $330.9 million ($3.25) in 1975. Revenues were $8.4 billion compared with $7.7 billion.

For the final quarter, Conoco earned $96.9 million (9) cents) on revenues of $2.2 billion compared with $78 million (77 cents) a year earlier on revenues of $2.1 billion.

Chairman Howard W. Blauvelt attributed the gains to foreign petroleum operations and to coal and chemical production.

Greyhound Corp, net income dropped 24 per cent in the final quarter of 1976, primarily because of declines in passenger bus operations chairman Gerald H. Trautman said Tuesday.

Fourth-quarter net income was $19 million (43 cents a share) compared with $25 million (57 cents) for the corresponding period in 1975. Revenue was $938 million compared with $1 billion for the same period last year.

For 1976, net income was $77 million ($1.76), 5 per cent below the $81 million ($1.87) recorded in 1975. Revenue was $3.7 billion compared with $3.8 billion the previous year.

American Can Co. Reported profits of $1.08 a share for the final quarter of 1976, up from $1.06 a year earlier. For the entire year. American Can earned $5.10 a share, up from $4.32 in 1975.

Net income for the quarter was $21.6 million on sales of $744.44 million compared with $20.89 million on sales of $714.23 million.

Net for the year was $100.86 million on sales of $3.142 billion, up from $35.35 million on sales of $2.967 billion in 1975.

PPG Industries, Inc., said its earnings reached a record $151 million in 1976 and sales surpassed the $2 billion mark for the first time. That compared with earnings of $39 million $4.28 a share) in 1975. Per-share earnings in 1976 were $7.22, the company said. Sales in 1976 reached a record $2.25 billion compared with 1975 sales of $1.89 billion.

In the fourth quarter, earnings were $33.4 million ($1.60) compared with $20.5 million ($1.47) for the same period in 1975.

Board chairman Robisnon F. Baker said PPG's major lines of business set individual sales and earnings records last year. "The year saw substantial turnarounds in our glass and fiber glass businesses, which were severely depressed in 1975. And our chemical and coatings and resins business showed continued strength," he added.

American Brands, Inc., reported earnings decreases of 21 per cent for the fourth quarter and 19 per cent for the year.

The large tobacco firm said it earned $20.5 million (74 cents a share) for the quarter, down from the $25.9 million (97 cents) earned in the same 1975 period. Sales for the period were $1.04 billion compared with $1.05 billion.

For the year, American Brands said its earnings dropped to $122 million ($4.54) from $148.5 million ($5.63). However, sales for the increased to $4.13 billion from $4.06 billion in 1975.

American brands said its figures included the loss of $44.6 million ($1.74) in 1976, and of $5.958 million (23 cents) in 1975 from foreign currency adjustments. Its quarterly figures included the loss of $18.6 million (73 cents) in 1976, and of $10.1 million(47 cents) in 1975.