Financial General Bankshares Inc. and Maryland National Corp., two of the region's largest commercial banking firms, have reported record results for the first quarter of 1979.

Allegheny airlines, meanwhile, reported yesterday that March earnings increased over last year while a seasonal first-quarter loss was reduced.

Financial General, a bank holding company with Washington area assets second only to those of Riggs National Bank, said first-quarter profits rose 14 percent to $3.2 million (48 cents a share) from $2.8 million (42 cents) in the same 1978 period, not counting gains or losses from sales of securities.

President J. William Middendorf II attributed the first-quarter rise primarily to an increase in interest income resulting from higher levels of earning assets and higher interests rates on commercial loans.

Total loan vlume for the Financial General banks rose 12 percent in the past 12 months to $1.16 million on March 31. Deposits rose 6 percent to $1.84 billion.

The Washington banking firm, which is seeking to block an attempted takeover by Middle East investors, controls Union First National Bank of Washington, and First American Banks of Maryland and Virginia, among other holdings.

Maryland National Corp., The parent company of Maryland Natinol Bank, reported a 25 percent increase in first-quarter operating profits to $6.7 million (94 cents a share) from $5.4 million (75 cents) a year earlier.

Chairman Robert D. H. Harvey cited the same factors as those mentioned by Middendorf as well as sharply improved gains by non-banking subsidiaries. Average assets rose to $3.1 billion from $2.9 billion, and average deposits were $2.19 billion vs. $2.07 billion. Loan volume increased to $1.9 billion from $1.8 billion.

Allegheny Airlines, based at National Airport, reported a first-quarter loss of $6.8 million compared with a loss in the same 1978 period of $7.06 million.Revenues rose substantially to $141 million from $118 million.

During March alone, Allegheny posted earnings of $2.3 million compaerd with $2.1 million a year earlier. Historically, Allegheny has reported first-quarter losses, principally because of less travel during bad winter months.

The lower loss and improvement during March were attributed in part to the introduction of full service in new Florida markets on Feb. 1 as well as new service to Birmingham in January.