Flagler purchased the Miami-Dade County property in the early 1980s to provide land for future railway customers, according to Robert W. Anestis, president, chairman and CEO of publicly traded Florida East Coast Industries Inc., Flagler's parent company.

"However, South Florida's population growth, which has provided the catalyst for continued development westward into the Medley/Doral area, has translated into increased demand and higher property values," he said in a statement. "Consequently, and because we have a sufficient land inventory to support future development, we decided to sell this parcel."

Flagler, based in Jacksonville, owns, develops, leases and manages about 6.6 million sf of class A office and industrial space, which includes 343,000 sf under construction. The firm has developed more than 3.3 million sf of office and industrial space at Flagler Station. At full build-out, the park will have about nine million sf of commercial and industrial space, along with retail.