Higher sales of submarines as well as a strong performance from its newly acquired corporate jet division helped General Dynamics Corp. increase earnings nearly 16 percent in the third quarter, the Falls Church defense contractor said yesterday.

Profit rose 15.7 percent, to $184 million (91 cents a share), compared with $159 million (78 cents) in the year-ago period, while revenue soared 23 percent, to $2.22 billion.

The quarterly profit beat analysts' expectations by 2 cents a share. General Dynamics stock was down 43 3/4 cents, closing at $52.25.

For the nine-month period, General Dynamics posted a profit increase of 59 percent, to $682 million ($3.38), compared with $429 million ($2.12), on revenue that increased 21 percent, to $6.3 billion.

During the quarter, General Dynamics completed its acquisition of Gulfstream Aerospace Corp., maker of business jets, and three defense electronics businesses from GTE Corp.

"This was another solid quarter," said chairman and chief executive Nicholas D. Chabraja. "It is significant that the newly acquired businesses are being successfully and smoothly integrated into the company."

* Reynolds Metals Co. of Richmond reported net income of $36 million (56 cents) for the third quarter, down from net income of $202 million ($2.92) in the year-ago quarter. The net results for the third quarter of 1999 included after-tax merger expenses of $9 million (15 cents), while the third quarter of 1998 included a net operational restructuring gain of $201 million, or $2.91 per share, primarily from the sale of Reynolds North American Can Business to Ball Corp. and an extraordinary loss of $60 million (88 cents) for early extinguishment of debt. The company did not meet analysts' expectations of 69 cents a share for the quarter.

The company reported earnings of $61 million (95 cents) for the first nine months of 1999, compared with earnings of $111 million ($1.55) for the first nine months of 1998.

Reynolds reported revenue of $1.21 billion for the third quarter of 1999, compared with revenue of $1.37 billion for the same period a year earlier. The company reported revenue of $3.44 billion for the first nine months of 1999, compared with $4.48 billion for the first nine months of 1998.

* MedImmune Inc. of Gaithersburg said it earned $5.1 million in the three months ended Sept. 30, compared with a loss of $11.1 million, for the same period of 1998. The company said it had one-time expenses associated with the pending acquisition of U.S. Bioscience Inc. Without that factor, MedImmune would have earned $6.5 million for the quarter.

MedImmune's revenues are rising sharply on the success of a drug that prevents a severe respiratory infection in premature babies. For the first nine months of 1999, MedImmune said it earned $23.6 million. That compares with a loss of $16.4 million, for the same period of 1998. For the third quarter, revenue rose to $32.2 million, from $22.2 million in the year-ago period.

* Saga Systems Inc. of Reston said it earned $4 million (13 cents) for its third quarter ended Sept. 30. This compares with $6.8 million (21 cents) in the third quarter of 1998. Net income for the first nine months of this year was $14.5 million (46 cents), down from $18.4 million (58 cents) for the year-ago period.

Third-quarter revenues were $51.8 million, compared with $62.9 million in the third quarter of 1998. For this year's first nine months, Saga produced $161.3 million, down from $179.1 million in 1998.

The company said its third-quarter results reflected customer concerns over the year 2000 computer problem, which resulted in a decrease in product license fees.

* Landmark Systems Corp., a Reston software firm, reported net income of $362,000 (3 cents) in the quarter ended Sept. 30, a 79 percent drop from the $1.7 million (14 cents) it earned in the same period of 1998. The company earned $3.5 million in the first three quarters of this year, down 8 percent from the $3.8 million it earned in the corresponding period last year.

Third-quarter revenue increased slightly, to $13.1 million, from $12.8 million a year ago. In the year-to-date period, revenue grew 16 percent, to $41.6 million, from $35.9 million in the prior year.

* BTG Inc. of Fairfax, an information services firm, yesterday said net income for its second quarter ended Sept. 30 was $1.1 million (12 cents), up from $93,000 during the same period last year (1 cent).

Revenues for the second quarter were $63.9 million, down from $87.7 million during the same period last year.

For the first six months of its fiscal year 2000, BTG reported net income of $2 million on revenue of $130.2 million.

* Creditrust Corp. of Baltimore said earnings increased to $6.3 million in the third quarter of 1999, compared with a net loss of $700,000 for the same period last year.

The company, which buys and collects delinquent consumer debt, attributed the gain in 1999 to an increase in revenue and a slower growth in expenses.

For the first nine months of 1999, the company earned $13.6 million ($1.35), up from $2.8 million (43 cents) from the first nine months of 1998.

* First Mariner Bancorp of Baltimore said third-quarter earnings increased 38 percent, largely because of gains in loans and deposits.

The company, parent of First Mariner Bank, earned $250,968 (8 cents) for the three months ended Sept. 30, up from earnings of $180,991 (5 cents) for the year-ago period.

For the first nine months of 1999, the company earned $694,124 (22 cents), up from $486,233 (15 cents).

* Central Virginia Bankshares Inc. of Powhatan, Va., said earnings for the third quarter were $483,243 (25 cents), up 1.4 percent percent from $476,340 (25 cents) for the same period last year. The per-share earnings remained flat because there were a smaller number of shares outstanding last year.

For the first nine months of 1999, the company said earnings were $1.41 million (74 cents), compared with $1.37 million (72 cents) for the first nine months of 1998.

* Provident Bankshares Corp. of Baltimore reported $11.3 million (43 cents) in third-quarter net income, a 14.2 percent gain over the $9.9 million (37 cents) earned in the year-ago quarter.

During the quarter, consumer loans increased by 24 percent as nearly 16,000 new retail checking accounts were opened. Core deposits were 5 percent higher than in the same quarter in 1998. The company announced a dividend of 16 cents per share, payable on Nov. 12, an 3.2 percent increase from the June 1999 dividend.

* Crestline Capital Corp., the Bethesda-based hotel company that was spun off from Host Marriott Corp. last spring, said acquisitions of new properties helped it earn $10.5 million (51 cents) in the quarter ended Sept. 10, nearly doubling the pro forma results that Crestline would have reported had the spin-off occurred at the beginning of last year.

Revenue at Crestline, which manages and operates Host Marriott hotels and living residences for seniors, totaled $969.4 million, up 4.4 percent from pro forma revenue in the 1998 quarter.

* RWD Technologies Inc. in Columbia yesterday reported a sharp drop in net income.

For the third quarter ended Sept. 30, the technology consulting company's net income fell to $20,000, with no earnings per share, from $3.5 million (22 cents) for the same quarter in 1998.

The company's chairman and chief executive, Robert W. Deutsch, blamed the poor performance on the year 2000 problem that "cut heavily into [RWD's] primary sources of revenue--information technology and enterprise resources planning services."

Revenue during the quarter fell marginally, to $29.1 million, from $30.2 million.