Arthur Rubloff & Co. has arranged for National Con-Serv Inc., which performs services for the Federal Insurance Administration's federal crime insurance program, to occupy 25,000 square feet in the Exchange Place building on Hungerford Drive, Rockville.

Also, Rubloff arranged for Myers Associates to take 21,000 square feet in a building at 12276 Wilkins Ave., Rockville. The Meyer firm is a clearninghouse for the issuance of multiple credit cards.

Julien J. Studley was the agent that arranged for Garnett Co. to lease 10 floors of the area's tallest high-rise at 1000 Wilson Blvd. in Rosslyn in one of the largest leasing deals in the metropolitan area.

The H.G. Smithy Co., a 50-year-old commercial real estate firm located since its founding in the Southern Building at 811 15th St. NW, plans to relocate Aug. 21 to 24,000 square feet in the new building at 1100 Vermont Ave. NW.

Coakley & Williams Inc. announced that OAO Corp., a systems engineering firm, has signed to occupy 60,000 square feet, effective Sept. 1, in the new Maryland yworld Trade Center building in Greenbelt. Cecile Barker, head of OAO, said the firm will make its corporate headquarters in the new building.