Martin Marietta Corp. cited the cost of its takeover battle with Bendix Corp. yesterday in reporting a fourth-quarter loss and a 54 percent drop in profits for all of 1982.

The Bethesda-based aerospace company said that heavy interest costs incurred in the battle--in which the company borrowed $900 million to fight off Bendix's merger overtures--cut into earnings.

The company, which had said previously that it expected to post poor results, lost $2.4 million in the fourth quarter compared with a profit of $38.6 million ($1.04 a share) in the same period in 1981. The company said its operating earnings of $5.4 million in the quarter were more than offset by the costs of closing two plants owned by its cement division. Martin Marietta is attempting to sell the cement unit for about $300 million to help reduce the company's debt.

For the year, Marietta earned $91.6 million ($2.92) compared with $200.1 million ($5.39) a year ago. Revenues in the period rose 6 percent to $3.5 billion from $3.3 billion. Although the company's aerospace operations, which include several major missile programs, were strong in 1982, its other operations, including cement, aluminum, chemicals and sand and gravel, had off years, company officials said.

When the month-long battle with Bendix ended in late September, Bendix was taken over by Allied Corp., which also got a 39 percent stake in Martin Marietta.

Virginia Electric & Power Co., fired by generating units setting a modern-day company performance record, announced a 12 percent earnings increase for 1982 yesterday.

Vepco, based in Richmond, posted earnings of $278.6 million ($1.98 a share) in 1982 compared with $237.9 million ($1.77) the year before. Vepco's operating revenues for 1982 were $2.4 billion compared with $2.2 billion in 1981.

Fourth-quarter earnings were $72.8 million (50.7 cents) compared with $67.1 million (50.6 cents). Revenues increased to $585.1 million from $555 million.

Vepco President William Berry said a cut in oil-fired power generation to 4 percent from 8 percent in 1981, along with 12 coal-fired generating units that set a company performance record, helped produce an increase during a year plagued by "severe economic difficulties."

The sale of a portion of Vepco's Bath County pumped storage project in 1981 resulted in payments of $194 million from Allegheny Power System and "significantly reduced our financing costs for 1982," Berry said.

Ethyl Corp. yesterday reported a 4 percent increase in net income for 1982 to $94.17 million ($4.68), and a 10 percent boost in fourth-quarter net income to $26.13 million ($1.30).

Richmond-based Ethyl said that its net income for the fourth quarter was a record for that period and that its yearly earnings were the second best in the company's history.

Those figures compare with annual earnings of $90.9 million ($4.56) and fourth-quarter earnings of $23.9 ($1.20) in 1981.

Net sales for 1982 decreased 8 percent from $1.8 billion to $1.6 billion, and sales for the final quarter were down 11 percent from $430.3 million to $383.6 million.

Net income for the year includes results of First Colony Life Insurance Co. from May 14, 1982, when it was acquired by Ethyl. After deducting costs related to the acquisition, First Colony contributed approximately $4.5 million to Ethyl's 1982 net income.

"Our plastics and coal operations continue to be quite adversely affected by the economy," said Ethyl Chairman F.D. Gottwald Jr. "However, in view of the unfavorable effects of the slow economy on the rest of the chemical industry, we are quite pleased that Ethyl's chemical operating results were significantly ahead of last year.

"We also are pleased with the positive results of First Colony Life Insurance, which continues to perform up to our expectations."