MIW Investors of Washington, a diversified real estate investment company, reported a 35 percent increase in profits during the first quarter. Its net income rose to $1.8 million (30 cents a share) on revenue of $17.5 million from $1.3 million (23 cents) on revenue of $9.3 million a year ago.

President William H. Savage cited the record level of loan originations and mortgage banking activities of its subsidiary, First American Savings & Loan. New loans amounted to $93 million, up from $53 million the previous year, and sales in the secondary market leapt from $19 million to $33 million.

*Computer Entry Systems Corp., a Silver Spring manufacturer of cash management and payment processing systems, experienced a 35 percent rise in earnings in the first quarter. Net income totaled $391,000 (7 cents a share) on revenue of $17.5 million versus $290,000 (7 cents) on revenue of $8.2 million a year earlier.

The price per share reflects the larger number of shares outstanding as a result of CES' acquisition in January of part of the assets of the Business Systems Division of General Instrument Corp. GIC product lines had losses of $6.7 million for 10 months prior to the acquisition.

*Planning Research Corp., a professional services company in McLean, announced that earnings for its third quarter that ended March 31 were $1.7 million (25 cents a share), up 20 percent from $1.4 million (21 cents) in the same period last year. Revenue rose to $118.9 million from $93.9 million.

Nine-month profits were $5.6 million (84 cents) versus $3.7 million (56 cents) in 1985.