American Motors Corp. reported record sales and profits yesterday for the first three months of 1979 as Jeep sales boomed.

AMC said it earned $32 million for the three months, which constitute the second quarter of its fiscal year. That was equivalent to $1.06 per share.

In the same quarter last year, AMC earned $2.67 million (9 cents a share).

Sales for the quarter were up 21 percent from $640 million to $773 million.

Though automobile sales declined 23 percent, Jeep sales rose 41 percent to a record 63, 436 vehicles from 44, 944 the previous year.

For the first half of the fiscal year, AMC earned $58.2 million ($1.92 a share) on sales of $1.5 billion. The company made $4.6 million (15 cents) on sales of $1.2 billion in the same period a year earlier.

Profits for the 1979 quarter include a tax credit of $7 million (23 cents). The 1978 quarter included a credit of $1 million or 3 cents a share.

Dow Chemical Co. reported a 36 percent increase in first-quarter profits, caused in part by the oil crisis and the threat of shortages.

Net income for the first three months of this year was $176.5 million (97 cents a share) compared with $129.5 million (71 cents) in the same period of 1978. Sales rose 26 percent to $2.08 billion from $1.65 billion for the first quarter of 1978.

"It's unlikely these percentage increases will continue through the year, since, since it appears that a certain amount of demand is to rebuild inventories," said G.J. Williams, financial vice president for Dow.

"We also should note that our year-to-year percentage increases is 'helped' to some extent by the transportation tie-ups in the U.S. during the 1977-78 winter, which depressed sales and earnings during the first quarter of 1978," he said.

Two of the nation's largest airline companies reprted first-quarter losses yesterday, with the slack travel season in late winter listed as one of the reasons.

Trans World Corp., holding company for Trans World Airlines, said it lost $47.8 million in the first quarter compared with a $37.6 million loss in last year's first quarter. Revenues increased 11.2 percent to $841.3 million from $756.5 million.

In addition to the airline, Trans World also owns Canteen, a food service firm, and Hiltion International, which operates hotels overseas.

At American Airlines Inc., the first-quarter loss was $6.8 million, virtually matching the performance of the year-earlier quarter, when the carrier lost $7 million. Revenues were $673.3 million, up 12.8 percent from $596.7 million in the first quarter of 1978.

Albert V. Casey, chairman and president of American, said the results were encouraging despite the loss because of large increases in fuel costs in the first quarter. "Our fuel expense in the quarter totaled $142.1 million," he said. "That is $23.2 million, or 19.5 percent more than we paid for fuel in the first three months of last year."

RWA Chairman L. Edwin Smart said, "These quarterly results reflect principally the adverse impact of accelerated cost inflation during the historical seasonal trough which our airlines operations experience in this period."

Gannett Co. Inc., a nationwide newspaper concern, reported a 22 percent gain in first-quarte earnings to 69 cents a share from 57 cents in the same period last year.

In the latest quarter, Gannett earned $18.45 million compared with $15.16 million in the first three months of 1978.

First-quarter operating revenues rose to $168.72 million from $148.48 million.

Allen H. Neuharth, chairman and president, said advertising linage was up 10 percent during the first quarter "despite some fierce winter weather in the West and Midwest." Gannett also logged a daily circulation gain of about 1 percent, he said, while Sunday circulation climbed by more than 4 percent.

Neuharth said the proposed merger between Gannett and Combined Ommunications Corp., which, owns television and radio stations, has been approved by shareholders of both companies and it awaiting action by the Federal Communications Commission.

Gannett owns 78 newspapers in the United States, Virgin Islands and Guam.

McGraw-Hill Inc. a publishing combine, earned 53 cents a share in the first quarter, up from 43 cents a year ago, as sales rose to $174.09 million from $153.58 million.

Net income rose to $13.25 million from $10.54 million.

Chairman Harold W. McGraw Jr. said the 26 percent profit gain was doubly significant because of heavy expenses incurred during the quater in fighting off the takeover bid by American Express Co.