City aviation officials plan to spend $5.5 million to acquire 15 acres near Philadelphia International Airport as part of a plan to develop an airfreight complex serving a broad swath of the region.

Worldwide Express is moving its Philadelphia office from Center City to the 1200 Intrepid Ave. office building in the Navy Yard business park being developed by Liberty Property Trust.

A massive, mostly vacant land parcel beside Philadelphia International Airport could become a bustling shipping hub for everything from medicine to car parts under a plan to develop the site into a new air-freight complex serving a swath of the northeastern United States.