Amazon leased this building in Seattle’s South Lake Union neighborhood, currently home to Microsoft and Group Health Cooperative. (Microsoft Photo)

Amazon has done it again.

The ever-growing online retail giant leased another big office building in Seattle, the 320,000-square-foot Westlake Terry building in the South Lake Union neighborhood, where Amazon first planted its flag in 2007. Kilroy Realty Corp., the Los Angeles-based owner of the building, announced the 12-year lease Monday.

“We love working in the heart of Seattle and are looking forward to moving into another great office space,” John Schoettler, Amazon’s director of global real estate and facilities, said in a statement.

Amazon’s growth alone, and how much it has juiced the Seattle office market, is a big deal. The company has said it could occupy 12 million square feet of office space in Seattle by 2022. But there is another twist to this deal. Amazon will be taking over the space from its cloud computing rival from the other side of Lake Washington, Microsoft. Microsoft has about 126,000 square feet in the building.

The Westlake Terry building, which is also occupied by Group Health Cooperative, is Microsoft’s only remaining presence in Seattle. In 2011, it closed Pioneer Studios, a funky office in Seattle’s Pioneer Square neighborhood where it built consumer electronics.

It is unclear if Microsoft plans to look for another office space in Seattle, and the company did not immediately respond to a request for comment.

Amazon has been taking buildings left and right, even as it continues to build its massive new campus on the north edge of downtown Seattle. The company just opened the second office tower on that campus, which is home to the Amazon Go grocery concept. Just across the street from that project, crews are building out Amazon’s third block. The company also has a fourth block in the neighborhood, where permit records show it is planning to build approximately 860,000 square feet of office space.

Just a month ago, Amazon inked a lease for a 21-story building just a few blocks from the new campus. That followed an announcement in October that Amazon plans to lease five floors of the old Tommy Bahama headquarters in South Lake Union. That came just a couple weeks after news that the online retail giant is opening a new office across Lake Washington in Bellevue, where it recently completed a lease for 354,000 square feet of office space.

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