Washington Gas Light Co. yesterday reported a net loss of $5.6 million in the normally weak third quarter ended Sept. 30, substantially reduced from a loss of $9.5 million in the same period last year.

Another regional utility, Baltimore Gas & Electric Co., reported a slight increase in profits for the same period. Earnings totaled $30.2 million (85 cents a share) compared with $28 million (81 cents) a year earlier.

The Washington Gas loss in the recent quarter came on revenues of $43 million, up sharply from $29 million in the 1976 period. Because of a heavy use of natural gas for winter heating in the area, WGL's profits in the summer quarter are always depressed.

For the 12 months ended Sept. 30, the gas company said its profits climbed to $20 million ($3.93 a share) from $9.5 million ($1.49) in the previous comparable period. Revenues rose to $313 million from $245 million.

Excluded from earnings for the recent year was an extraordinary credit of $1.4 million (32 cents a share), from settlement of a lawsuit, which brought net income to $21 million ($4.25).

Baltimore Gas earnings for the same 12-month period declined to $100.5 million ($2.81 a share) from rose to $775 million from $703 million. A hearing examiner for Maryland's public service commission has approved BG&E rate increases of $69.5 million for electricity and $17.5 million for gas, a decision subject to a final decision within 30 days by the agency.

Financial General Bankshares, Inc., a Washington bank holding company, yesterday reported higher operating profits for the third quarter and first nine months of 1977.

Net earnings of the firm in the recent quarter declined to $2.7 million (43 cents a share) from $3.9 million (63 cebts) ub the same period last year. However, the 1976 results included a one-time gain of $1.3 million (22 cents) from selling subsidiaries.

Similarly, Financial General's final earnings for the first nine months declined to $7.7 million (S1.2 a share) from $8.3 million )$1.34) last year.

Once nonrecurring gains are excluded, however, the nine-month profits from actual company business rose 7 per cent to $7.2 million $1.16) vs. $6.8 million ($1.09).

The Washington company sold interests in four banks and a bank service firm in the Chicago area during the second and third quarters of 1976, which added to earnings for those periods. Profits for the first nine months of 1977 also included a one-time gain of $423,000 (7 cents) from selling Financial General's investment in the H. G. Smithy Co.

Chairman J. William Middendorf II said yesterday that his firm's operating gains reflected primarily the growth of loans and investment securities. Total deposits of company banks rose 8 per cent in the past year to $1.5 billion on Sept. 30 while loan volume increased 11 per cent to $883 million.

Financial General's 15 banks have resources of $2.1 billion and include Union First National of D.C., Alexandria National, Arlington Trust Co., Clarendon Bank & Trust. Peoples National in Leesburg, American Bank of Silver Spring and Round Hill National.

Acacia Mutual Life Insurance Co. and United Services Life Insurance Co., both based in Washington, reported higher sales and income for the first nine months of 1977.

Investment income of Acacia was $32.1 million compared with $30.9 million in the same period last year as sales increased 19 per cent to [WORD ILLEGIBLE]million. Total assets rose to $712 million from $688 million at the beginning of the year.