Michael J. Casey, who owns his own five-office realty firm in Maryland, has been elected president of the Prince George's County Board of Realtors.

The Anne Arundel County Board of Realtors has chosen Chris Coile as its Realtors of the Year. Awarded the same honor in 1973, he is the first member of that board to receive the designation twice.

Marc Earl Rosendorf, 18, has acquired a real estate sales license in Maryland and joined the Bethesda firm of Harvey Rosendorf Inc., headed by his father. The younger Rosendorf is a student at the University of Maryland.

The Washington Board of Realtors will elect officers at its annual meeting on Thursday. Kenneth J. Luchs of the Shannon and Luchs firm is the nominee for president.

Washington architect David Norton Yerkes has been named to the board of Georgetown consultants of the Commission of Fine Arts. The advisory committee reviews all new construction and alteration proposals in the historic Georgetown area of Northwest. He replaced Anne Vytlacil, who resigned.

John C. (Jake) Broderick has been elected president of the Washington Building Congress. He is vice president and a director of the Washington office of the Leo A. Daley Co.

Lyn Anderson has been named manager of the Crofton office of Long & Fosters Realtors. In real estate residential sale since 1974, she was formerly assistant manager of the office.

E. Loraine Kent has been named sales manager at the Wood Edge of Signal Hill, a community of houses being built by Kettler Brothers Inc. in Burke.

The National Savings and Loan League will hold its annual convention in Kansas City starting Sunday. Speakers will include Republican candidate for president Ronald Reagan,economist Walter Heller and Jay Janis, the new chairman of the Federal Home Loan Bank Board.