Four years after arranging for the acquisition of the 116-acre Pentagon City site near a Metro station in Arlington, a company headed by New York City brothers Daniel, Frederick and Elihu Rose is moving ahead with their plan for a $1 billion mixed-use development that has been envisioned for 30 years.

The 10-year project of Rose Associates now focuses on the nearly completed 12-story, 250,000-square-foot building on the site opposite the Pentagon and just north of Crystal City. The latter is an even larger total development of office buildings, luxury apartments and hotel sparked by the Charles E. Smith Cos. over the past 20 years.

An undreground passageway will link the first Pentagon City office building to the Metro station at 12th and South Hayes streets.Completion is scheduled this winter.

The next phase will include another large office building nearby and 620 condominium apartments. Both office buildings were designed by architect Vlastimil Koubek to provide views of the Pentagon and downtown Washington. Salus Corp. is doing the construction, and Coldwell Banker will handle leasing.

Plans already approved by Arlington County, after a long zoning process, include creation of a total 1.25 million square feet of office space, 5,900 apartments, 2,000 hotel rooms and 800,000 square feet of commercial space.

Rose Associates recently did a large new office building on Dewey Square in Boston.