Four oil companies reported higher second-quarter profits yesterday.

Gulf Oil Corp., the nation's fifth largest oil company, reported a 4.3 per cent gain in profits to $2.6 million ($1.11 a share) on revenues of $4.82 billion from $208 million ($1.06) in earnings on sales of $4.29 billion in the second quarter of 1976.

In the first half, profits fell from $406 million ($2.08) a year ago to $382 million ($1.96).Sales rose from $8.63 billion to $9.66 billion.

The Union Oil Co. of California, the 14th-largest U.S. oil firm, announced a 41 per cent rise in second-quarter profits to $75.2 million or ($1.95 a share). In the second quarter of 1976, the firm recorded earnings of $53.2 million ($1.49).

Second-quarter sales were $1.5 billion compared to $1.4 billion last year.

Ashland Oil Co. the 15th-largest U.S. oil company, announced third-qarter fiscal 1977 net earnings of $36.2 million ($1.23 per share), as opposed to $30.8 million ($1.12) in the same period of 1976.

Sales for the quarter ended June 30 totaled 1.2 billion, compared with $1.01 billion in 1976.

Atlantic Richfield Co. reported an increase in second quarter profits rose to $191.2 million ($1.57 a share) on sales of $3.24 billion from $135.7 million ($1.19) on sales of $2.11 billion a year ago.

Pan American World Airways, Inc. reported second quarter net earnings of $17.8 million (27 cents per share) compared to $101.3 million ($2.40) a year ago.

The airline said the contrast between the two quarters was due to a $98.4 million extraordinary item in 1976's second quarter from a debenture exchange.

Revenues for this year's second quarter were $478.3 million, compared to $408.2 million last year.

Meanwhile, UAL, Inc., parent company of United Airlines, announced second-quarter net rose 69.9 per cent to $81.2 million ($1.25 a share) from $18.4 million (73 cents) a year ago.

Revenue for the nation's largest domestic carrier was $809.3 million compared to $739.9 million in last year's second-quarter.

Lockheed Aircraft Corp reported an increase in second-quarter profits to $13.4 million (80 cents per share) compared to $11.3 million (85 cents) in the same period a year ago. The sales figures for the period are not available yet.

Lockheed's 1977 earnings reflect the dilution effect of warrants to purchase common shares issued in connection with the company's October 1976 financial restructuring.

Kennecott Copper Corp., the nation's largest copper producer, yesterday reported a slight rise in second-quarter profits to $10.5 million (32 cents a share) on sales of $281.5 million, up from $10.1 million (30 cents) on sales of $259.5 million a year ago.

The company also detailed terms of the previously announced sale of Peabody Coal Co. for $1.2 billion in cash and securities.

Kennecott said it received $235 million cash, including an installment payment of $135 million for the U.S interests and payment in full of $100 million for the Australian interests, $365 million of non-negotiable Peabody Holding Co. notes payable Jan. 3, 1978 at prime rate, $200 million of 20-year notes which carry an interest rate of 9.5 per cent, but are not marketable until Jan. 3, 1978, and 400 million of 30-year subordinated income notes at 5 per cent interest.