NEW YORK CITY — San Francisco-based Shorenstein Properties has selected New York City-based Aragon Properties to complete nine pre-built office suites totaling 47,000 square feet at two of its midtown Manhattan office buildings. The majority of work will take place at 850 Third Avenue, Shorenstein’s 21-story office tower. Aragon will build out five units on the 16th floor that will total 23,400 square feet and range in size from 3,300 to 6,900 square feet. Completion is scheduled for July. In April, Shorenstein delivered three built-out suites on floors 10 and 21 of the same building. Each of the pre-built suites will feature a reception area, an open area for workstations, at least one conference room and a minimum of four private offices. The spaces are designed to appeal to a wide range of tenants and when leases are signed, Shorenstein will order modifications of the spaces to suit the tenant’s needs.