Heck's Inc., regional retailers and wholesalers based in Nitro, W. Va., reported a 21 percent increase in earnings from continuing operations to $87.965 million in the first quarter of 1983, compared with $72.946 million in the same period of 1982.

The company reported net earnings of $426,000 for the first quarter (5 cents a share), compared with net income of $50,000 in the first quarter of 1982 and a loss per share of 6 cents. The Rouse Company of Columbia, Md., reported a jump in net earnings from $1.688 million in the first three months of 1982 to $2.49 million in the first quarter of 1983. Net earnings per share climbed from 11 cents to 16 cents, the company said.

Revenues for the first quarter were up from $37.366 million to $42.725 million.

Stewart Sandwiches Inc., of Norfolk, last week reported revenue for the January-to-March period of $10.49 million, with a net loss per share of 10 cents. In the same period during 1982, revenues were $11.71 million with a net profit per share of 3 cents. For the nine months ended March 25, 1983, revenues were $35.4 million, down 9.8 percent from the same period for fiscal 1982. Micros Systems Inc. of Beltsville, Md., said revenue in the 13-week period ending March 26 was up slightly from $3.455 million a year ago to $3.727 million. Net income climbed more substantially, from $19.8 million to $174.3 million. Nine-month revenue totaled $10.668 million, up 16 percent from the first three quarters of fiscal 1982, while net income for the nine months ending March 1983 was up 108 percent to $153.7 million. Union Trust Bancorp of Baltimore, parent of the Union Trust Co. of Maryland, reported net income for the first three months of 1983 of $4.2 million ($1.70 per share), up 11 percent from $3.8 million ($1.53) in the first quarter of 1982. Earnings before securities transactions rose by 14 percent over the same period a year ago.

Total assets for the three-month period ending March 31 averaged $1.7 billion, a 13 percent gain from $1.5 billion a year ago. Total deposits, at $1.2 billion, are up 10.2 percent of the $1.1 billion average of the first 1982 quarter, the company said.

Bank of Maryland, in Hillcrest Heights, reported a 32 percent increase in net income for the first three months of 1983 compared with a year earlier. The rise, to $353,000 ($1.20 a share), was due to higher net interest earnings, the bank said. Deposits rose by $16.7 million, or 19 percent, to $103.4 million, while assets increased to $111.8 million from $98.8 million.