Reynolds Metals Co. yesterday announced a 50 percent jump in 1979 profits, figures that continue the Richmond-based company's massive growth at the end of the decade.

The company reported profits of $177.7 million ($9.25 a share) for the past year, up from 1978 profits of $117.8 million ($6.11).

Reynolds' sales jumped 18 percent over 1978, increasing from $2.8 billion to $3.3 billion.

A major factor in Reynolds' profits jump was the fact that the company cut its foreign currency and exchange lossed from $30.4 million in 1978 to $14.8 million last year.

Reynolds' fourth quarter profits last year were $44.4 million ($2.31) up from $38.1 million ($1.99) in 1978.

In other reports Equitable Bancorporation reported 1979 profits before security transactions of $14.16 million ($3.74), compared to $13.01 million for 1978.

Equitable also reported fourth quarter profits of $3.60 million (95 cents) for 1979, compared with 1978 fourth quarter profits of $3.57 million (94 cents).

The Baltimore-based bank holding company reported that total average deposits rose in 1979 to $1.732 billion, up from $1.554 billion in 1978.

The company's board also announced a 5 percent stock dividend payable May 16, 1980, to shareholders of record on April 17, 1980.

The First American Bank of Virginia also reported its first full calendar-year profits, announcing 1979 profits of $8.2 million, up from $6.4 million in 1978.

First American was formed in April 1978 following the merger of Clarendon Bank and Trust, The Alexandria National Bank and the Arlington Trust Co.

The company attributed its increasing profits to growth in loans and interest income.In 1979, loan volume increased by 16% over 1978, the company said.

In addition, The Farmers and Mechanics National Bank, of Frederick, Md., reported 1979 profits of $2.15 million ($3.62), up from $1.83 million ($3.08) in 1978.

The banks total assests increased from $217 million 1978 to $230 million for 1979.