Oracle Corp, Belmont, California has moved quickly to expand its new Oracle Complex Systems Corp systems integration subsidiary in Arlington, Virginia by buying Bethesda, Maryland integrator Falcon Systems Inc. It sees Falcon providing a strong Federal mar-keting counterpart to the commercial thrust it has been pursuing at Oracle Complex. It is taking only the Falcon Systems arm of the company, which has been in Federal sys-ems integration for six years and last year did $44m of business, and not Falcon Microsystems offshoot, which sells Apple computers to Uncle Sam; terms were not disclosed.