Washington Mutual Investors Fund, the largest equity-based mutual fund in the Washington area, has announced the retirement of its chairman and cofounder, Bernard J. Nees.

Nees dreamed up the investment concept for the fund as a partner in the local brokerage firm of Johnston, Lemon 33 years ago. At 77, he is now one of the old hands in the Washington broker-dealer community -- a fraternity that includes George Ferris Sr., chairman of the investment firm of Ferris & Co., and Harvey B. Gram Jr., chairman emeritus of Johnston, Lemon.

"It all started in 1929 when I was going to law school at night," Nees said in a recent interview. "I got a job as cashier of Johnston, Lemon, where I began working with lawyers who were handling estates and trusts." Working with trustees and lawyers involved in that area eventually gave Nees the idea for a fund that would invest in common stocks on the District's Legal List, a listing of securities approved by the District for investment in trust funds. Nees still serves Johnston, Lemon -- one of the original investors in the fund -- as executive vice president and director emeritus.

The fund's board of directors elected Stephen Hartwell, currently president, to succeed Nees. Hartwell also is senior vice president and a director of Johnston, Lemon.

James H. Lemon Jr., chairman and chief executive officer of the brokerage house and formerly vice president of the fund, has been elected the fund's vice chairman. And Harry J. Lister, formerly executive vice president of the fund and a senior vice president of Johnston, Lemon, has been named to replace Hartwell as president. Finally, Ralph S. Richard, treasurer, and Howard L. Kitzmiller, secretary, have been named vice presidents, in addition to their current responsibilities.

Washington Mutual Investors Fund, with assets of about $700 million, was among the top 15 financial institutions in Washington, Maryland and Virginia last year. FINANCIAL SERVICES

After its recent annual meeting, the Washington investment firm Ferris & Co. announced a number of new officers: Theodore W. Urban, senior vice president and a member of the board of directors; Daniel G. Shannon, senior vice president; Martin J. Bambrick Jr., Maria L. Clendenin, LuAnn K. Fendlay, George M. Ferris III, Renee Frederick, Charles H. Lee, Stephen C. Lehman, Ronald S. Maslanka, Maurice E. May, Steven S. Ross and Anton Salah, vice presidents, and Patricia G. Abbiss, assistant vice president.

First American Bank of Maryland has announced these recent promotions: Stephen A. Horvath, formerly area president and senior corporate banking officer at BancOhio National Bank, has joined the bank as senior vice president with responsibility for corporate banking in Montgomery and Prince George's counties. Thomas P. Gallup, who has worked as an analyst in credit administration, has been named corporate banking officer for metro Washington. And Lynda C. Waldeck, formerly with Ann Arbor Trust Co. in Michigan, was named a credit administration officer.

Annapolis Federal Savings & Loan Association has appointed Geoffrey L. Hess controller of the S&L. A graduate of St. Mary's College, Hess spent two years as controller of PATS Inc. in Columbia, Md. PROFESSIONAL SERVICES

Eric R. Zausner, head of the energy practice at Booz Allen & Hamilton Inc., has been given the additional responsibility of managing partner of the consulting firm's operations in the western and southwestern United States. Before joining the firm in 1976, Zausner served as deputy administrator of the Federal Energy Administration, the Energy Department's forerunner, and as deputy assistant secretary for energy in the Interior Department. Zausner, formerly based in the firm's Bethesda offices, will move to San Francisco.

Touche Ross & Co. has announced two appointments in its Washington Service Center, an office specializing in government policy work: Gillian M. Spooner, formerly with the Joint Committee on Taxation, where she drafted legislation, has joined the firm as a partner. Donald J. Drees, previously an assistant director in the office of chief counsel of the Internal Revenue Service, has been named a tax manager.

Intertel has appointed Thomas A. Kennelly vice president and general counsel, the management security consulting firm announced. Kennelly has been deputy chief of the Justice Department's organized crime and racketeering section, an assistant U.S. attorney, and most recently, an attorney with the firm Diuguid, Kennelly & Epstein.

Sandra A. Chesrown, formerly the project director of Fairfax County's Metro study, has joined Kerns Group Architects as director of marketing and senior planner. COMPUTERS

General Electric Information Services Co., as part of a restructuring designed "to better leverage its network services and communications expertise into specialized market areas," has named W. James McNerny Jr. senior vice president in charge of its combined business development and U.S. marketing operations. McNerny has made the following promotions within the new division: Ruann E. Pengov, previously general manager of office communication operations, to vice president and general manager for business communications; David Foster, formerly general manager for business logistics and electronic data interchange, to vice president and general manager for focused business operations; and John E. Sidgemore, previously vice president and general manager of the Eastern sales area, to vice president in charge of U.S. sales and services. COMMUNICATIONS

Former Olympic kayaker David Halpern, who also did promotional work for the 1984 summer Olympic games, has joined the editorial staff of the Kamber Group, a Washington public relations firm, as a staff writer. In other appointments, Sandy Kyle Bain, a veteran Washington writer and producer, has been appointed assistant director of the media productions division. Mary Pat Cooney, previously with PrePress studio in Alexandria, and Larry Matthews, formerly with Photocomp Inc. in Lorton, have been named production manager and designer, respectively. Finally, Madelyn Reiss, who most recently coordinated production of the Congressional Record, has joined the firm's administration division.

C & P Telephone Co. has appointed Jeffrey S. McDermott, a former network services division manager for Bell Atlantic, C & P's parent company, as treasurer. A 17-year veteran of the phone company, McDermott will also have responsibility for financial planning and capital recovery.

Colin Williams, formerly manager of international affairs at TRT Telecommunications Corp., has moved over to American Satellite Co. as director of its international business services division. American Satellite is a partnership between Fairchild Industries Inc. and Continental Telecom Inc.

AT & T has named A. J. (Herb) Linnen, formerly public relations director for AT & T Communications, to succeed Pic Wagner as media relations director in its Washington public relations office. Wagner is retiring after 29 years as a public relations executive with AT & T and the former Bell System.

Fibertrak, a fiber-optics partnership between Norfolk Southern Corp. and Santa Fe Southern Pacific Corp., has appointed Bruce G. McPhee vice president for finance and Donald C. Thompson controller. McPhee, recently treasurer of Southern Pacific Co. in San Francisco, replaces Robert J. McLean, who has retired. Thompson, an accountant, was formerly assistant controller of Southern Pacific Co. GOVERNMENT

The Virginia Department of Economic Development has tapped Patrick A. McMahon of Reston to be the state director of tourism and deputy director for economic development, effective June 17. McMahon, currently director of membership programs with the Travel Industry Assocation of America, succeeds Marshall Murdaugh, who left the agency in December.

Donald H. Vandrey, energy and technology planner for the City of Rockville since 1978 and cable television coordinator for the past two years, has been appointed public information officer by City Manager Larry N. Blick.