Criterion Insurance Co., a Wahington-based automobile insurance affilate of Geico Corp., has reported lower earnings for the second quarter and first six months of 1979.

With auto repair costs soaring, Criterion's underwriting profits from insurance operations plummeted to $19,000 in the recent quarter compared with $808,000 a year earlier. Investment income rose slightly, however, to $1.37 milliion from $1.31 million and net earnings before extraordinary items were $1.24 million (84 cents a share) compared with $1.51 million ($1.03) a year ago.

Couunting the tax loss benefits in the 1978 period, net income was $1.31 million and net earnings before extroardinary

Counting the tax loss benefits in the 1978 period, net income was $1.97 million ($1.35 a share).There were no one-time gains in the recent quarter.

In the first half. Criterion earned $2.07 million ($1.41 a share) compared with $2.88 mmillion ($1.97) a year ago, which included a tax loss carryforward gain of 32 cents a share. Criterion suffered a loss a loss from underwriting insurance of $723,000 in the rencent six months compared with profits last year of $456,000.

International General Industries Inc., a diversified industrial packaging, machinery and energy firm partially owned by International Bank of Washinton, reported record six-month profits of $6.3 million ($3.57 a share) compared with $4.6 million ($2.60) a year ago. Revenues rose 23 percent to $59 million.

IGI revenues do not include the business of Foster Wheeler Corp., an international engineering, manufacturing and construction group which had revenues of $821 million vs. $726 million and which is 10 percent-owned BY "IGI and affiliates.

International Bank and IGI currently are discussing a merger.

Stanwick Corp., an Arlington-based manapement systems firm, reported earnings of $902,421 (87 cents a share) in the year ended April 30, down from $1.56 million (1.50) a year earlier. Sales declined to $18 million from $20.3 million.

Both revenues and profits were adversely affected by the Iranian revolution, since Standwick had to withdraw a majority of employes in that nation who were working on a major contract with Iran's Navy. Costs of the withdrawal and a sharp decline in revenues led to a quarterly loss in the final three months of $753,000 -- the first loss in nearly six years.

Because of the loss of Iranian business, it will "take some time" to achieve prior revenue levels through acquistion of new contracts, Stanwick stated.