Led by International Business Machines Corp., computer firms reported higher first quarter earnings yesterday, showing the continuing strong demand for data processing equipment.

IBM reported profits of $667 million, or $4.57 a share, for the first quarter, up 13.2 percent from last year's first quarter earnings of $589 million or $4.01 a share.

That gain paled in comparison to those of other computer companies. Control Data said profits were up 59.2 percent, Burroughs Corp. earnings were up 26.0 percent, and NCR said its profits on continuing operations climbed 77.7 percent.

"Purchases of data processing equipment increased substantially," IBM Chairman Frank T. Cary said. "However, the effects of this strong purchase volume on net earnings were offset to some extent by rising costs and expenses, reflecting the buildup of the company's resources as well as the increasing effects of inflation."

IBM's results were also hurt by foreign exchange lossed of $38 million in the quarter, compared to a gain of $30 million in last year's first quarter.

Burroughs, based in Detroit, reported earnings rose to $42.2 million, or $1.03 a share, from $33.5 million or 82 cents in the same period last year. Sales climbed 16.5 percent to $588.4 million.

Burroughs Chairman Paul S. Mirabito said sales "reflected a resurgence of customer demand following a period of new product announcements by the industry."

CNR Corp., based in Dayton, Ohio, said earnings on continuing operations were $30.1 million or $1.13 a share, up from $16.9 million or 63 cents a share.

The 1978 quarter results were restated to exclude NCR's Appleton Papers subsidiary, which has since been sold. It originally reported earnings of $22.9 million or 85 cents a share.

Control Data Corp. reported earnings of $25.0 million or $1.45 a share, up from $15.7 million or 90 cents a share in last year's quarter. Revenues for the Minneapolis-based computer business climbed 23 percent to $492 million while those for the firm's Commercial Credit subsidiary were up 10.3 percent to $225 million.

RCA's Corp. reported first quarter earnings yesterday, but said profits of its NBC subsidiary were down. CBS reported a decline in profits.

RCA profits for the first three months of the year were $62.1 million or 81 cents a share, up 13.1 percent from $54.9 million or 72 cents a share in the same quarter of 1978. Revenues climbed 20 percent from $1.5 billion to $1.8 billion.

CBS reported earnings declined 47.3 percent to $17.8 million or 64 cents a share from $33.8 million or 64 cents a share in the same period of 1978. Revenues increased 11.3 percent from $744.2 million to $828.3 million.

Westinghouse Electric Corp. First three months of 1978 reaching $83.2 million, or 96 cents a share, the company reported yesterday.

The company attributed the improvement to wider profit margins due to increased volumes of business. Sales in the quarter were $1.78 billon, 15.3 percent ahead of the 1978 quarter.

General Electric Co.'s business improved broadly in the first quarter, Chairman Reginald H. Jones said yesterday.

Earnings were up to $303.4 million or $1.33 a share from $247.8 million or $1.09 a share a year ago. Sales spurted to $5.08 billion from $4.44 billion. The sales gain was 14 percent and the profit rise 22 percent.

Jones said the profit again was helped by a lower effective tax cost and higher interest earnings of General Electric Credit Co. In spite the gains, Jones said his company's economists will are predicting an economic slowdown in the second half of this year.

Celanese Corp. disclosed yesterday at its annual meeting it had a 58 percent rise in earnings for the first quarter from a year ago.

Profit was $32 million or $2.17 a shar on sales of $745 million, up from $20 million or $1.37 a share a year earlier, when first quarter sales were $607 million.

Of the per share profit, 32 cents came from domestic polyester and nylon production, 47 cents from acetates, 18 cents from international fiber operations, 95 cents from chemicals, and 29 cents from plastics. There was a loss of 4 cents a share of polymer specialties.

Mead Corp., the paper glant, earned $1.17 a share in the first quarter, up from 88 cents a year ago, on a rise in sales to $618.77 million from $522 million. Net income climbed to $29.96 million from $19.27 million.

President Warren L. Batts said the improved profit and sales came from lumbering as well as paper operations and packaging products. Mead's coal, metal castings and rubber businesses also did well.