PERSONNEL FILE . . . Oliver Cowan of Merrill Lynch Realty/Chris Coile Inc. has been named the top Merrill Lynch sales associate in the United States. Cowan, who racked up sales of more than $ 13.5 million last year, ranked No. 1 in a sales force of 8,300. Recognized repeatedly over the past decade by the Washington Board of Realtors, he has received 35 awards in the past 13 years. . . The Federal National Mortgage Association has appointed Raymond J. McClendon, currently a housing official with the City of Atlanta, as its vice president of community development. . . Jay Janis, a former undersecretary of Housing and Urban Development and a past chariman of the Federal Home Loan Bank Board, and George Sternlieb, director of the Center for Urban Policy Research at Rutgers University, have been named consultants to the U.S. League of Savings Institutions' Home Ownership Task Force. . . The Artery Organization has oppointed Roger A. Blair, formerly of Lincoln Properties Inc. in Pittsburgh, as an assistant vice president and division manager.

THE BUSINESS . . . The new office and retail complex being developed by the Oliver T. Carr Co. at 1255 23rd St. NW won a first place award in the recent EnComp '82 energy conservation competition. The building was cited for its contribution to energy conservation through design and construction. The architects for the project are Keyes Condon Florance. Mechanical/electrical engineering is by Girard Engineering, and the general contractor is the George Hyman Contruction Co. . . . A group of real estate companies in Northern Virginia have formed a joint referral and support program to be known as the Independent Brokers Council. Initial membership includes Cooper Realty of Fredericksburg, Harding Realtors of Warrenton, Hearthstone Properties of Burke, Fred Hetzel and Associates of Leesburg, Hometown Properties of Herndon, Jordan-Rummel Realtors of Woodbridge, Annie Lauler Corp. of McLean, Mary Price, Realtor of Falls Church, Rector Associates of Alexandria and Stedman Realtors of Annandale . . . C.J. Cross & Associates, a Northern Virginia commercial mortgage banking firm, announced that it recently arranged and closed more than $45 million in financing. Included is participation of $6.15 million for the renovation of the former Perpetual American headquarters building at 11th and E Sts. NW. The 87,000-square-foot building, owned and being renovated by Rozansky & Kay, is expected to be ready for occupancy by the end of the year. Total financing on the project exceeds $12 million.

ON THE MOVE . . . The Washington law firm of Cooter, Gell and Cooter has leased more than 20,000 square feet--an entire floor--at 1333 H St. NW, becoming the largest tenant to date in the building, which contains 261,232 square feet. The law firm had been at 1110 Vermont Ave. NW. Arthur Rubloff & Co. handled the transaction . . . American Bell Inc., a computer/communications firm, has taken nearly 18,500 square feet in the Crystal Gateway II building in Crystal City. The building is owned by Second Gateway Associates. Cushman & Wakefield represented the lessee . . . The Evans Co. of McLean announced that it has a contract to purchase the Fairmont Building at 4420 N. Fairfax Dr. in Arlington. The five-story, 40,000-square-foot building will be ready for leasing this summer. The site is zoned for mixed use and has development potential of up to 250,000 square feet.