UNC Resources Inc. said yesterday that its earnings for the year climbed to $17.7 million (81 cents a share) compared with a loss of $122.2 million ($6.90) during 1984.

Sales for the Falls Church company were up 27 percent to $352.9 million from $278.8 million during the same period last year.

Net earnings for the year included a gain from a litigation settlement, a loss from the discontinuance of the machine-tool business and an additional provision for discontinued mineral operations.

For the fourth quarter, UNC posted earnings of $6.3 million (29 cents) compared with a loss of $134.9 million ($6.18) during the same period a year ago. Sales during the fourth quarter jumped 91 percent to $129.5 million from $67.8 million during the fourth quarter of 1984.

UNC restructured itself radically in the last year, from a failing diversified conglomerate into a focused manufacturing and services company. The firm now provides high-technology services and products in the aerospace/aviation, telecommunications and nuclear areas.

"A small experienced management team is now in place to provide clear direction and leadership to the company . . . " said President Dan A. Colussy.

*Atlantic Research Corp. of Alexandria reported that earnings grew 31 percent in 1985 to $15.2 million ($2.05 a share) from $11.7 million ($1.57) in 1984.

The company, a manufacturer of solid-fuel rocket propulsion systems, also said that fourth-quarter earnings were $3.7 million (50 cents) compared with $3.1 million (41 cents) in the same period a year ago.

Sales improved 14 percent over the year, from $205.6 million in 1984 to $234.3 million in 1985. Fourth-quarter sales for 1985 totalled $66.9 million compared with $56.6 million in the same period a year ago, the company said.

*BDM International Inc. reported that its net income for the year rose 31 percent to $10.5 million ($1.04 a share) from $8 million (81 cents) during 1984. Revenue for the McLean firm also rose 31 percent to $250.3 million from $191.4 million during the previous year.

President Earle C. Williams said that the company's contract awards more than doubled last year to $441 million. BDM provides professional and technical services in national defense and security, mostly for the U.S. Armed Forces.

For the fourth quarter, net income climbed to $3.3 million (32 cents) on revenue of $73.7 million from $2.3 million (24 cents) on revenue of $55.2 million during the same period the year before.

Syscon Corp. reported that its net income for the year climbed 9 percent to $4.4 million (95 cents a share) from $4.1 million (87 cents) during 1984. Sales jumped 13 percent to $117.2 million from $104 million.

For the fourth quarter, net income rose to $1.19 million (26 cents) from $1.18 million (25 cents) during the same period in 1984. Sales climbed to $32.7 million from $26.6 million.

Net income in the fourth quarter was reduced by a higher-than-expected tax rate due to a lower-than-expected investment tax credit compared with 1984, the company said. Syscon, based in Washington, is a high-tech company that evaluates, develops and manages computer software systems and hardware/software products.

Investors Savings and Loan Association reported that its net income for 1985 rose 73 percent to $7.38 million ($1.82 a share) from $4.27 million ($1.58) during the previous year.

For the fourth quarter, net income for the Richmond thrift dropped to $1.3 million (21 cents) from $1.9 million (68 cents) during the same period of 1984.

In the fourth quarter, Investors realized extraordinary income of $1 million, which included a $912,000 reduction in income-tax expense resulting from the utilization of a net operating loss carry forward.

Investors, which operates 22 retail-banking branch offices, has announced plans to acquire Citizens Savings and Loan of Richmond.