Perpetual Federal Savings and Loan Association of Washington will have a new chairman next week. But the name is familiar.

Directors of the area's largest thrift institution yesterday elected Thomas J. Owen, 44, to take over as board chairman.

Owen, who also will continue as president and chief executive officer, succeeds his father, Thornton W. Owen, who steps down next Wednesday after a 43-year career at Perpetual.

Thornton Owen, 75, long has been one of the leading members of Washington's business establishment but he has preferred to work behind the scenes. He became board chairman of Perpetual in 1956 and a decade later he switched jobs with then-President Edward C. Baltz. In 1975, son Thomas Owen became president and Thornton Owen continued as chairman.

In another action yesterday, Steuart Petroleum Co. President Leonard Steuart II was elected to the S&L's board.

Founded in 1881 as the outgrowth of a group called the St. George's Society, who pooled their resources on a loan basis to help a member buy a new home, Perpetual has 12 offices in the District and suburban Maryland with assets exceeding $1 billion.

The S&L, whose assets more than doubled under the leadership of Thornton Owen, currently is involved in a major challenge to federal regulations prohibiting new branches across state lines into the suburbs -- an issue the Federal Home Loan Bank Board agreed to consider earlier this week.

Thomas Owen, like his father, is a native of Washington. The incoming chairman lives in the Maryland suburbs and was president of the Washington Board of Realtors in 1971. At 35, he was the youngest person ever to head the group.

The new Perpetual chairman also has been a director of the National Association of Realtors, resident of the D.C. Kiwanis Club, director of the Metropolitan Washington Board of Trade and director of the D.C chapterof the American Red Cross.

Steuart, the new director, heads a major fuel oil supplier in the D.C. area. He also is president of the Independent Fuel Terminal Operators Association, chairman of the board of St. Albans School and a director of the Board of Trade.

Thornton Owen joined the Board of Trade in 1932 and was active in area civic and business activities ever since. He headed a real estate appraisal firm, Thomas J. Owen & Sons, established by his grandfather in 1896.

He was honored in 1971 by the Board of Trade with its top honor -- "man of the years."