Two of the nation's steel makers and five of seven oil companies yesterday reported dramatically lower third quarter results.

Bethlehem Steel Corp., the nation's second largest producer. lost $477 million ($10.92 a share) for the third quarter compared with a profit a year ago of $45.5 million ($1.04).

For the first nine months. Bethlehem reported a net loss of $407,4 million ($10.70) compared with profits last year of $128.3 million ($2.94). Sales in the recent period were $1.29 billion compared with $1.32 billion a year ago.Nine month revenue were $4 billion compared with $4.1 billion a year ago.

The company said both the third quarter and nine-month result were adversely affected by a pre-tax charge of $750 million resulting from the shutdown of some facilities and by a charge of $40 million for expenses related to flood damage at its Johnstown. Pa., plant.

Following the July 20 flood, Bethlehem laid off 7,300 employes at its Johnstown and Lackawanna, NV., plants.

"We believe the closing of mareinal facilities and either actions taken leave Bethlehem in a stronger and leaner condition to take advantage of opportunities for profit and growth," said chairman Lewis W. Foy.

Foy said that $167 million of the $750 million pre-tax charge represents the writeoff of closed facilities and does not involve any expenditure of cash. Another $100 million will be used for termination of operations.

The remainder approximately $483 million, represents the estimate of benefits payable to terminated employes in future years.

Allegheny Ludlum Industries Inc., a specially steel produce said third quarter profits dropped 40 per cent from a year earlier to $3.3 million (25 cents a share) compared with 1976 third quarter earnings of $5.3 million (52 cents).

Sales rose slightly from $214.6 million to $223 million in the period.

Allegheny Ludlum said it earned $142 million ($1.34) for the first nine months on sales of $720.3 million compared with $25.7 million $2.91 on sales of $652.6 million in the same period a year ago.

Chairman Robert J. Buckley said he was encouraged by Allegheny Ludlum's operating result in the face of difficult obstacles.

"Some segments of the business notably industrial, magnetic and electronic specialities and automotive thermostats, are enjoying record levels of business," he said.

Standard Oil Co. of California, the fourth largest oil firm in the U. S. said its third quarter earnings increased to $238 million ($1.40 a share) from $224 million ($1.32) last year. Sales were up to $5.6 billion from $5.2 billion.

Nine months profits rose to $743 million ($4.36) compared with $612 ($3.60) a year before on sales of $16.5 billion versus $14.9 billion.

Union Oil Co., the 14th largest oil firm, reported higher quarterly earnings of $95.5 million ($2.10 a share) from $73.8 million ($1.64) a year earlier. Union's revenues were $1.49 billion against $1.42 billion.

Nine month earnings rose to $253.2 million ($5.59) against $199.4 million ($4.44) a year before. Revenues were $4.52 billion against $4.32 billion.

But Mobil Corp., the nation's third largest firm, said earnings fell to $239 million ($2.26 a share) from $252 million ($2.39) last year. Nine month earnings rose to $702 million ($6.63) against $679 million ($6.58).

Mobil based in New York, refused to release revenue figures.

Cities Service Co., said its quarterly earnings fell to $402 million ($1.45 shares) from $563 million ($2.09) a year before.

The reduced earnings came on higher revenues of $1.05 billion compared with $963.6 million a year ago.

For the first nine months, profits dropped to $155.9 million ($5.66) from $157.4 million ($5.80) a year before. Revenues rose to $3.26 billion against $2.81 billion.

Downturns in its minerals operations and the increasing costs of exploring for oil resulted in the declines, the company said.

Marathon Oil Co., reported a decline in third quarter earnings to $49.6 million ($1.65 a share) form $64.1 million ($2.13) in 1976 on revenues of $1.12 billion versus $9.29 million.

Marathon's nine-month net was $139.9 million ($4.65) against $136.6 million ($4.55) on revenues of $3.38 billion versus $2.73 billion.

Pennzoil Co., said third quarter earnings fell to $27.1 million (78 cents a share) against $29.9 million (87 cents). Revenues rose to $272.1 million from $271.9 million.

Nine month profits dropped to $39.4 million ($2.59) from $94.2 million $2.73). Sales increased to $845.5 million versus $805 million.

Getty Oil Co., reported lower quarterly earnings of $66.4 million $3.21 a share) from $67.3 million ($3.50). Sales rose to $844.5 million from $793.3 million.

The firm's nine month profits rose to $224 million ($10.98) from $187.5 million ($10.01). Sales increased to $2.59 billion from against $2.4 billion last year.