Investment and securities holding company Legg Mason Inc. yesterday reported a 30 percent increase in its fiscal second-quarter earnings, but still fell short of Wall Street's expectations.

The Baltimore-based firm reported earnings for the quarter ended Sept. 30 of $28.3 million, or 47 cents a share, which fell short of the 52 cents a share forecast by market research firm First Call/Thomson Financial.

Raymond A. Mason, chairman and chief executive of Legg Mason, attributed the firm's disappointing results to fluctuations in the market, which affected the company's investment banking subsidiary.

Legg Mason was only the second securities brokerage--the other was Bear Stearns & Co.--to miss analysts' expectations. Legg Mason's stock closed at $33.50 yesterday, down 12 percent.

The company added that investment advisory revenue grew 35 percent, to a record $126.3 million. Investment advisory revenue constituted 42 percent of the firm's total revenue in the second quarter.

Legg Mason has 125 branch offices and employs about 1,250 brokers.

* Comsat Corp. of Bethesda reported a loss of $18.4 million for the third quarter.

The company blamed the loss on the write-off of the satellite telecommunication company's $36 million direct investment in ICO Global Communications Ltd., a start-up company promising a global network of hand-held satellite telephones that filed for bankruptcy protection last August.

The third-quarter results compare with net income of $6.6 million (12 cents) in the same quarter of 1998.

* Constellation Energy Group Inc. of Baltimore said its third-quarter net income declined 15 percent because of $32 million in charges from selling its interest in an insurance firm, and other expenses.

The owner of Baltimore Gas and Electric Co. had earnings of $136.1 million in the quarter ended Sept. 30, compared with $160.9 million in the year-earlier period.

The holding company took a $17.3 million write-down related to its insurance investment. It also took $10.1 million in charges to liquidate several real estate positions and end a California power project. Expenses related to Hurricane Floyd resulted in $4.9 million in charges.

Revenue rose 4 percent, to $970.4 million, in the quarter, from $934 million in the comparable period a year ago.

* Newport News Shipbuilding Inc. said its third-quarter profit rose 18 percent, to $20 million (58 cents a share), compared with earnings of $17 million (46 cents) in the same period last year.

Revenue at the Virginia shipyard dipped slightly, to $451 million from $462 million. Gains in its business of servicing Navy ships were offset by declines in aircraft carrier construction revenue, the company said.

Newport News was also able to reach a new labor agreement with its unionized workers following a strike.

* Century Bancshares Inc. of Washington, which operates six bank branches in the area, reported a 90 increase in its third-quarter net income, mainly due to its expansion into the Maryland and Virginia suburbs.

Earnings for the quarter ended Sept. 30 rose to $323,000 (12 cents a share), from $170,000 (6 cents), in the year-ago period. Assets were $201.3 million at the end of the quarter, up from $160 million at the end of the comparable period in fiscal 1998.