Two large American computer makers yesterday reported substantially higher earnings in their latest quarters, Burroughs Corp. saying its revenue increased 41 percent over last year and Apple Computer Inc. reporting it had reversed its large losses from last year.

Meanwhile, Rockwell International Corp. reported higher earnings, and the parent firm of American Airlines Inc. showed a substantial revenue decline.

Burroughs, which is based in Detroit, reported second-quarter net income of $76.2 million ($1.61 a share) compared with $54.1 million ($1.19) in the second quarter of 1985.

For the first half this year, Burroughs reported net income of $92.2 million ($1.97), down 8 percent from $100.7 million ($2.22) in the corresponding period last year.

Chairman W. Michael Blumenthal said the low value of the U.S. dollar against foreign currencies helped Burroughs' performance overseas.

Apple reported that earnings for its third quarter, which ended June 27, were $32.3 million, compared with a loss of $17.2 million for the same period a year ago.

A company spokesman at its California headquarters said the improvement in gross margins in part reflects Apple's efforts to continue to control its costs.Rockwell International Corp. said yesterday that its third-quarter profits edged higher by 2 percent to $163.3 million ($1.10 a share) on sales that rose by 7 percent to $3.1 billion. The company reported net income of $160.2 million ($1.07) on sales of $2.9 billion a year earlier.

Profits for the first nine months of the company's fiscal year declined 1 percent to $449.4 million ($3.01) from $455.3 million ($3.06) in the 1985 period. Sales rose nearly 10 percent from $8.2 billion to $9 billion.

Quarterly earnings in the Pittsburgh company's aerospace business rose primarily due to increased production of the B-1B bomber. AMR Corp. reported second-quarter earnings declined by more than 26 percent to $128.2 million ($2.07 a share) from $173.9 million ($2.98) last year. Officials attributed the slippage to intense pricing competition for American Airlines.