In another indication of the shakeout in the federal computer market, Federal Data Corp. of Bethesda announced yesterday that it has agreed to sell its Integrated Office Systems Corp. division to Everex Systems Inc., a California-based manufacturer of personal computers.

Federal Data President Dan Young said that the Gaithersburg-based IOS division was too small for Federal Data to run profitably in the increasingly competitive federal computer market.

IOS sells personal computers, minicomputers and microcomputers to the government.

But Everex sees opportunity in IOS.

Everex has worked closely with IOS in the past, and the companies have successfully bid on contracts together. In a statement, Everex said the purchase will enable it to increase its presence in the government marketplace. Everex stock closed down 50 cents yesterday at $6.62 1/2.

Everex said it plans to continue to operate IOS as an independent subsidiary and retain all the workers already in place.

Young said he does not expect any layoffs or other changes at IOS.

IOS has about 90 employees and annual sales of about $35 million. As part of the sale, Everex will acquire IOS government contracts calling for the sale of approximately $200 million of computers over the next five years.

Young said yesterday that the sale of its IOS division will enable Federal Data to concentrate on its core business, that of designing computer networks and communication systems for the government and for the commercial sector. After the sale, Federal Data will have about $100 million in sales and about 100 employees remaining.