Mobil Corp., Sun Co. Standard Oil of California and Cities Services Co. reported higher third-quarter earnings, benefiting from increased gasoline demand in recent months.

Mobil, the nation's No. 2 oil company and fourth largest industrial firm, said earnings increased to $259 million ($2.44 a share) from $239 million ($2.26) a year ago.

Revenue for Mobil was $9.1 billion, up from $8.5 billion a year earlier.

For nine months, Mobil earned $795 million ($7.50), up from $702 million ($6.63) a year earlier. Nine-month revenue figures were not released.

The Montgomery Ward retail division contributed $39 million to Mobil's nine-month profits, $4 million more than a year earlier, and Container Corp. contributed only $13 million, down from $35 million a year earlier.

Sun, the 10th largest oil producer, said earnings were $97.1 million ($1.82 a share) compared with $94.9 million ($1.86) a year ago. The drop in per share earnings is a result of an increase in the number of Sun shares outstanding. Sales rose to $1.89 billion from $1.57 billion last year.

Profit for nine months were $270.9 million ($5.06) on sales of $5.476 billion compared with $269.1 million ($5.51) a year earlier on sales of $4.677 billion.

The third-quarter profit was depressed additionally by a $9 million write-off of surplus inventory at the Sun Shipbuilding & Drydock subsidiary.

Standary of California, No. 4, reported a 12 percent gain in third-quarter profits to $1.54 a share from $1.39 a year ago on a rise in revenues to $6.6 billion from $5.6 billion.

Nine-month profits were $748 million ($1.38) on revenues of $17.8 billion compared with $734 million ($4.31) a year ago on revenues of $16.5 billion.

Cities Services, the 15th largest, reported third-quarter net income of $52.6 million ($1.91 a share) a 31 percent increase over the $40.2 million $1.45) the company earned in last year's third quarter. Sales in the quarter were $1.14 billion, up from $1.05 billion a year ago.

Nine-month profits declined by 5 percent to $148.3 million ($5.36) from $155.9 million ($5.66) a year earlier as revenues increased to $3.48 billion from $3.27 billion.

Bethlehem Steel Corp., which lost $477 million in the 1977 third quarter, reported earnings of $64.7 million for the period this year, the nation's second largest steel maker said yesterday .

The net earnings are equivalent to $1.48 a share. Last year's loss was equal to $10.92 a share.

Net income for the first nine months was $150.6 million ($3.45 a share) compared with a net loss of $467.4 million ($10.70) in 1977.

Last year's results were depressed by a pre-tax charge of $750 million resulting from a plan to close down certain steel making facilities and a $40 million pre-tax charge reflecting estimated expenses of a flood in the Johnstown, Pa., area.

Total revenues were $1.57 billion in third quarter of 1978 and $1.29 billion in the 1977 third quarter. Shipments of rolled steel and other finished products were 3.2 million net tons in the latest quarter and 2.9 million net tons in 1977.

Bethlehem said it produced 4.8 million net tons or raw steel in the quarter compared with 3.8 million net tons for the same period in 1977.

For the first nine months, Bethlehem reported revenues of $4.56 billion in 1978 and $4.05 billion in 1977. Production of raw steel was 13.8 million net tons for the first nine months in 1978 and 12.5 million net tons in 1977.

Procter and Gamble Co. said increased unit sales boosted its first fiscal quarter profit to $166.9 million (2.02 a share) from $150 million ($1.82) a year ago.

The leading soap maker and food company said it had sales of $2.28 billion dollars in the quarter ended Sept. 30 compared with $1.93 billion a year ago.

And two other major manufacturers of food products reported higher earnings.

General Foods Corp. said its net earnings rose 74 percent in the most recent quarter from depressed earnings a year ago. Nablsco Inc. reported an 8 percent increase in profits for the latest fiscal quarter.

General Foods said its earnings came to $49.44 million (99 cents a share) on sales of $1.28 billion for the quarter ended Sept. 30, which is the second of its fiscal year. The company cited recovery in its world wide coffee business. In the 1977 period, the company reported earnings of $28.43 million (57 cents) on sales of $1.19 billion.

For the first half, General Foods said earnings came to $106.28 million ($2.13) up 34 percent from profits of $79.17 million ($1.59) a year earlier. Sales rose from $2.46 billion to $2.64 billion.

Nabisco's net income in the quarter ended Sept. 30 totaled $23.7 million (73 cents a share) on sales of $546.4 million. In the comparable third quarter of 1977, earnings came to $22 million (71 cents) on sales of $508.4 million.

In the first three quarter, Nabisco earnings came to $67 million, up from $47.9 million last year.

Johnson and Johnson, a leading health care products company, posted a 19.3 percent increase in its third-quarter profits because of a better performance of its international business.

The company earned $80.4 million ($1.35 a share) compared with $62.1 million ($1.06) in the 1977 third quarter as sales rose to $888.5 million from $744.8 million.

For the nine months, the company earned $238.2 million ($4.01) compared with $190.4 million ($3.26) a year earlier. Sales increased to $2.62 billion from $2.20 billion.

Anhenser-Busch Inc. announced record sales and earnings for the third quarter and first nine months of 1978.

August A. Busch III, chairman of the board and president of the world's largest brewer, reported net income for the third quarter of $38.5 million (85 cents a share) on sales of $771.6 million, up from $30.6 million (68 cents) on sales of $629 million during the same period last year.

Sales for the first nine months were $2 billion, resulting in net earnings of $92.2 million ($2.04), up from $75.3 million ($1.67) in 1977.

Busch said the record-setting beer volume sales of 11.6 million barrles in the third quarter and 31.6 million barrels in the nine-month period reflected the company's strong market penetration. Sales volume for the first nine months represents about 24.3 percent of total brewing industry sales, including imports, according to the United States Brewers Association.

Busch said the record-setting beer volume sales of 11.6 million barrles in the third quarter and 31.6 million barrels in the nine-month period reflected the company's strong market penetration. Sales volume for the first nine months represents about 24.3 percent of total brewing industry sales, including imports, according to the United States Brewers Association.

Busch said the company's established beers - Budweiser, Michelob and Busch - "performed impressively," while the new beers - Natural, Michelob Light and premium-priced Busch - also were doing well.

Gox Broadcasting Corp. reported higher revenues and earnings for both the third quarter and the nine months ended Sept. 30.

Net income for the three-month period was $8.7 million ($1.30 a share) compared with $5.1 million (80 cents) for the same period a year ago an increase of 70 percent. Operating revenues for the 1978 third quarter were $58 million, up from $45.2 million in the same period last year, an increase of 28 percent.

Nine-month net income was $23.5 million ($3.52), an increase of 42 percent for comparable earnings of $16.5 million ($2.73) for the same period last year. Operating revenue for the nine months of 1978 increased 20 percent to $162.9 million from $135.3 million in 1977.

Broadcasting revenue was up 26 percent for the third quarter over the same period in 1977, and television reported strong gains in both national and local advertising, the report said.