A second major area commercial bank has launched a "loan sale," and the bank that introduced the concept here most recently - American Security Bank of Washington - is about to unveil at aggressive marketing program aimed at increasing auto loan business.

A third bank, meantime, is offering a mail-order course in personal financial planning designed "to help anyone make the most of his or her money."

First Virginia Bank, the largest in Northern Virginia with $415.5 million of deposites on March 31, has reduced rates on loans at its 48 offices through June 15, according to president Robert H. Zalokar.

He said rates have been reduced in a number of categories, out he emphasized second-mortgage loans, on which rates have been sliced by 10 per cent.

Zalokar also said rates have been reduced for new auto, boat, tuition, recreation and personal loans "for any worthwhile purpose."

First Virginia and other banks around the country previously have promoted loan "sales" as a method of gaining new business, as have credit unions in the D.C. area over past years.

But American Security, the second-largest bank in the metropolitan area, gained wide attention for its strongly promoted loan sale at District branches on two Saturdays in April. Personal and home improvement loans rates were cut by 18 to 9 per cent for the two weeks.

On Wednesday, American Security plans to launch another promotional effort. According to Tim Holland, marketing vice president of the D.C. bank, the auto loan rates will be among the lowest in the area - 9 per cent for 36-month loans and 10 per cent for 48-month loans.

"This is an extension of our strategy to be as open as possible and clear about pricing" of loans, Holland said yesterday. Unlike the earlier promotion, the auto loan rates will continue indefinitely and are not limited to two weeks.

Holland said the money sale in April had been "highly successful," with loan numbers and dollar volume about three times what has been expected. He declined to provide specific information, but persons who applied for loans at the D.C. bank's crowded branches on the two Saturdays in question had to stand in line in some instances.

Zalokar, of First Virginia, said his bank has allocated "several million dollars" to the loan sale in Northern Virginia.

National Bank of Washington is the institution offering a six-lesson mail-order course that teaches the basics of investments, taxes retirement plans, trusts, will and estates. Students who enroll proceed at their own pace and, in the final lesson, begins to make a personal financial plan for the future.

NBW said it will send a critique to students at the end of each lesson; the course costs $36.

In a recent study of Washington area banking services, the publication "Washington Consumers' Checkbook" detailed a wide difference in consumer loan rates at various institutions.