Construction has been completed on a building in Alexandria that the American Association for Counseling and Development will use as its headquarters.

The four-story building, located at 5999 Stevenson Ave., contains 40,000 square feet of space. The association, formerly known as the American Personnel and Guidance Association, has leased the second and third floors of the building. Mount Vernon Realty Inc. has leased the first floor.

The building is owned by the Mason Hirst Companies of Annandale. It was financed through an Alexandria industrial revenue bond program by First and Merchants Bank.

The American Association for Counseling and Development represents about 40,000 professional counselors.

The $3.5 million project is the first of two phases of the planned Landmark Business Center, which will also include a ten-story, 150,000-square-foot office building and two restaurants.

Other recent developments in commercial realty in the metropolitan area:

* The National Pasta Association has relocated from Chicago to Arlington County. The association has signed a three-year lease for 1,700 square feet of space at 1901 N. Fort Myer Drive in Rosslyn.

* Glen Industrial Communications has relocated from Washington and leased an 8,000 square foot facility at 979 Rollins Ave. in Rockville.

* Systonetics Inc. has leased 2,500 square feet of office space at the Kossow Center at 380 Maple Ave. West in Vienna. Mineral Exploration & Development Co. has also leased 1,272 square feet of space at the Kossow Center.