Norfolk Southern Corp., the railroad company, said its profit fell 8 percent last year because of higher fuel and interest expenses as well as the cost of laying off employees.

The Norfolk firm's net income dropped to $556.1 million from $606.2 million in 1989. Because the company has been buying back its stock, net income fell less sharply on a per-share basis, dropping 1 percent to $3.43 per share from $3.48 a year earlier.

Revenue for the year rose 2 percent to $4.62 billion from $4.54 billion in 1989.

The company is the parent of Norfolk Southern Railway Co., which accounts for about 80 percent of its revenue, and of North American Van Lines Inc.

The company said its fuel expenses rose 40.5 percent in the year and its interest expenses doubled. It also took a $29.5 million charge in the fourth quarter to pay the expenses of reducing employment.

In the fourth quarter of the year, Norfolk Southern's profit fell 21 percent to $117.1 million (75 cents a share) from $148.2 million (87 cents) in the same quarter a year earlier. Revenue rose slightly to $1.12 billion from $1.11 billion a year earlier.

Baltimore Bancorp, the parent of the Bank of Baltimore, said yesterday that its earnings fell 49 percent in the year ended Dec. 31, to $9 million (71 cents per share) from $17.6 million ($1.36) in 1989.

Baltimore Bancorp said it lost $6.5 million in the fourth quarter, compared with a profit of $1.9 million (15 cents) earned in the same period in 1989.

Chairman Harry L. Robinson said that concern over the economy and the area's real estate market prompted the bank to add $18.9 million to its loan-loss reserve, the cushion that protects it against future losses.

The company, which has 51 banking offices in Maryland, had assets of $3.52 billion at year-end.

Jefferson Bankshares, parent of Jefferson National Bank, said yesterday it earned $15.1 million in 1990 ($2.20 per share), a slight decrease from the $16.9 million ($2.44) that the savings bank earned in 1989.

In the fourth quarter of 1990, the Charlottesville-based savings bank earned $3.9 million (57 cents), down 11 percent from $4.4 million (65 cents) earned in the fourth quarter of 1989.

Jefferson Chairman Hovey S. Dabney attributed the results to cost-cutting.

Jefferson, which operates 91 branches throughout Virginia, had assets of $1.5 billion at year-end.

Baltimore Gas and Electric Co. said that its profit fell last year because of higher operating, maintenance and financing costs and less favorable weather.

Net income for the year was down 29 percent, to $172.9 million ($2.10 per share) from $243.9 million ($3.05) in 1989. Revenue rose slightly to $2.2 billion from $2.0 billion in 1989.

In the fourth quarter, net income fell 45 percent to $19.4 million (23 cents) from $35.3 million (44 cents) in the same quarter a year earlier. Revenue fell to $484.3 million from $485.5 million a year earlier.

BG&E said it set aside a $35 million reserve to cover the possibility that Maryland's Public Service Commission might not allow some costs associated with the Calvert Cliffs nuclear power plant.