Amazon.com expects to begin moving into its new office space in mid-2010, with full occupancy in 2011. The company said in an SEC filing that it will pay as much as $1.5 billion over 16 years to occupy the full 1.6 million sf, and that is also has options for additional space. An Amazon executive was not immediately available Thursday morning for further comment.

The developers are billionaire Paul Allen's real estate investment arm Vulcan Inc., which controls some 60 blocks in the South lake Union area, and Schnitzer West, a partnership Schnitzer Investment Corp. of Portland, OR, and Dan Ivanoff of Seattle. To help seal the deal, the City of Seattle approved increased building heights in the immediate area and the developers agreed to contribute $6.4 million for affordable housing in the area.

Amazon.com's new headquarters will be anchored by three 12-story, 160-foot high buildings on one-and-a-half blocks bounded by Terry and Boren avenues and John and Harrison streets. The buildings are known as Interurban Exchange II, IV and V.