BDM International Inc. of McLean yesterday reported second-quarter net income of $5.2 million (43 cents per share), up 47 percent from $3.5 million (31 cents) for the same period in 1986.

Revenue for the period was $80.3 million, a 0.6 percent increase from $79.8 million for second quarter of 1986. Company officials said revenue for the quarter was below expectations, but that earnings for the year are expected to exceed past growth rates. The company said the jump in income was partly caused by the lower tax rates resulting from tax changes enacted last year.

For the first six months of 1987, net income was $9.7 million (82 cents), up 53 percent from the $6.4 million (59 cents) in the first half of 1986. Revenue was $160.3 million, a 6.5 percent increase from $150.5 million during the first half of 1986.

BDM is a technical and professional services firm in the area of national defense and security, energy, communications and other areas.

USLICO Corp. of Arlington reported that earnings for the second quarter were $10.6 million (94 cents), down 20.3 percent from$13.3 million ($1.19) a year ago. Revenue was $126.3 million, down 3.9 percent from $131.4 million in the second quarter of 1986.

USLICO said heavy storms in June caused its property and casualty companies to add $1.3 million to reserves for storm losses. Second-quarter results were also affected by changes in the tax law that increased USLICO's effective tax rate and reduced earnings by $1.2 million.

For the first six months of this year, earnings were $22 million ($1.95), an increase of 12.8 percent over $19.5 million ($1.73) for the first half of 1986. Revenue was $258 million, a drop of 1.2 percent from $261.2 million in 1986.

Star Technologies Inc., a computer company in Sterling, reported net income of $709,000 (4 cents) for the first quarter ended June 30, a sixfold increase from $119,000 (1 cents) for the same quarter in 1986. Revenue for the quarter was $9.1 million, a 9.5 percent increase over last year.