Amazon.com Inc. is in negotiations with the developer behind the Seaport Square project to lease all the space in a planned 18-story office building, enough space for 2,000 or more new employees, according to a new filing with the city of Boston.
The Seattle tech giant's lease could expand to up to 1 million square feet and 4,000 employees by 2025.
The deal represents a major expansion of Amazon's presence in Boston that is unrelated to its ongoing search for a second headquarters.
The size of the lease — 430,000 square feet to start with — was disclosed in a regulatory document filed Tuesday evening by WS Development, the developer behind the Seaport Square project.
The filing confirms information first reported by the Boston Business Journal in November that Amazon was on the hunt for between 500,000 and 1 million square feet in the Seaport District.
A footprint of 430,000 square feet represents the entire office space available in the 18-story Block L4 building in Seaport Square. But as a condition of signing that lease, Amazon would also have the option to expand into Block L5, the 610,000-square-foot building next door.
Amazon and WS Development are asking the city for a $5 million property tax break for each lease, in exchange for a commitment in each case that Amazon will hire at least 2,000 employees within the Greater Boston area.
Mayor Martin Walsh is expected to talk about the project Tuesday night.
"This project filing is the first step, and we’ll be working with Amazon to make it a reality," Walsh is planning to say, according to prepared remarks