Amazon.com plans to build up to 3 million square feet of new office space in three office towers on land that the company has agreed to purchase from the property’s longtime owner, according to a Seattle Times report today. The news confirms and adds new details to the rumors that have been swirling around the city’s commercial real estate community in recent weeks.

An expansion of that size would more than double the company’s presence in the area. Amazon occupies around 2 million square feet of space on its main headquarters campus and has been leasing additional space like mad on the neighboring blocks. The company leases a total of 3.4 million square feet of office space in North America, including its Seattle offices, according to its latest annual report.

The new properties are on the northern edge of downtown, bordered by 6th Avenue, Blanchard Street and Westlake Avenue, and connected to the rest of Amazon’s space by the city streetcar line championed by Microsoft co-founder Paul Allen’s Vulcan Inc., whose real-estate division developed the Amazon campus.

No word on the potential timeline for creating the new towers. As noted by the Seattle Times, the new office towers could be the first that Amazon would own outright, rather than lease. However, it’s not unusual for companies to sell their properties and lease them back.

Amazon.com has been adding employees at a rapid pace, and now employs more than 56,000 people.