American Security Bank and Citizens Bank & Trust Co. of Marland reported improved second-quarter earnings, with Citizens posting a 48 percent gain over 1981 profits and American Security recording a 6.6 percent increase over an exceptionally strong second quarter of 1980.

American Security earned $6.79 million ($1.89 a share) compared with $6.36 million ($1.75) in the same period a year ago. First-half profits increased 13 percent to just over $13 million ($3.36) from $11.5 million ($3.17) last year.

The smaller percentage gain in the second quarter did not indicate a slowdown in profit growth, said Chairman W. Jarvis Moody. Rather it reflects unusual strength during the second quarter of 1980, when American Security's profits showed a 30 percent jump.

Citizens Bank & Trust Co. of Maryland reported its net income rose to $3.778 million ($2.33 a share) for the three-month period from $2.553 million ($1.58) a year earlier. A spokesman for the bank said that increased earning from higher rates charged on loans and increased numbers of automobile loans contributed to the big jump in earnings.

For the first half of the year, total resources increased to $701.161 million from $643.244 million last year. That included an increase in time deposits from $304.786 million last year to $343.312 million. Capital funds increased from $64.702 million last year to $71.399 million.

Wards Co. Inc. of Richmond, operator of the Circuit City hi-fi stores in the Washington area, reported its first-quarter profits fell 8 percent to $278,000 (35 cents a share) from $303,000 (38 cents) in the same period a year ago.

Sales of the nearly 90 Wards stores jumped 20 percent to $33.1 million from $27.6 million.

President Alan Wurtzel listed three factors that he said kept earnings from increasing along with sales. Higher interest expenses cut profits by about $50,000 and another $50,000 decrease came from payments to settle a threatened lawsuit. Costs of completing the acquisition of Lafayette Radio and Electronics and preparing to open three new stores in North Carolina also hurt quarterly profits.

Gray Drug Stores Inc., which recently acquired Drug Fair Inc., reported an operating loss for the fiscal year ended an operating loss for the fiscal year ended May 2 but posted a profit from selling some of its operations.

Gray posted sales of $195.2 million for the year, up from $192.8 million in the prior year. Drug Fair's operations are not included in the figures because the acquisition was not completed until after the reporting period was over.

Gray reported a loss from continuing operations of $308,000 compared with profits of $2.72 million ($1.05 a share) the prior year. Discontinued operations produced an additional loss of $1.73 million compared with profits from those operations of $1.99 million the year before.

But a gain of $2.489 million from the sale of Gray's Rink's discount store produced a final profit of $454,000 (17 cents) for the yer compared with prior-year profits of $4.7 million ($1.81).

Computer Network Corp. reported a net loss of $103,000 for the fiscal year ended March 31, compared with net income of $930,000 (55 cents a share a year before.

Revenue was also down for the year -- $19.277 million compared with $21.242 million. The D.C. computer services company said the year's results reflected a one-time pretax charge of $386,000 associated with the expiration of a contract with the Enviornmental Protection Agency and pretax charges totaling $302,000 associated with additional depreciation and settlement of a legal dispute.