An apartment tower plan that’s gone through several revisions over the past decade in response to changing market conditions in Boston’s Seaport District has a new investor.

Atlanta-based multifamily developer Gables Residential has signed a 99-year ground lease with Massport for the 0.6-acre parcel at 501 Congress St., a surface parking lot next to World Trade Center station on the MBTA’s Silver Line. Wells Fargo Bank N.A. provided a $102 million construction loan. The parcel is currently approved for 307 units in 23 stories.

Boston-based Drew Co. completed a 20-story, 236-unit apartment tower in the phase 1A of Waterside Place in 2014 and obtained approval from the former Boston Redevelopment Authority in 2016 for the second building, containing 307 apartments, including 62 smaller “innovation units” and 15 income-restricted units.

Drew Co. President John E. Drew said recently that groundbreaking was delayed partly because of conflicts coordinating construction staging areas with Massport’s 1,620-space South Boston Waterfront Transportation Center garage on D Street. Groundbreaking originally had been scheduled for spring 2017.

Drew was not immediately available for comment, but a source familiar with the project said Drew Co. continues to be a participant. A Gables Residential spokeswoman did not return messages seeking details on the project timetable.

The project will include 84 second-floor parking spaces served by an automated stacking system, estimated at $157 million in 2016. Additional parking for residents is expected to be provided in the Massport garage.

The deed-restricted affordable units will rent for $1,065 to $1,600 per month and developers agreed to contribute $5.7 million to a city fund that supports affordable housing generation.