Share story’s planned Denny Triangle high-rise office complex took another big step closer to reality Thursday.

The fast-growing online retailer closed on its much-anticipated purchase of the three-block site. Amazon paid Seattle’s Clise Properties $207.5 million, according to county records.

The blocks are bounded generally by Sixth Avenue, Westlake Avenue and Blanchard Street.

Amazon plans to build a 3.3 million-square-foot office complex, including a 37- or 38-story tower and a smaller building on each of the blocks. The development would be downtown’s largest ever.

The Clise family had owned the three blocks, now mostly parking lots, for decades.

“It was very important to us to make something happen there, and Amazon is the perfect partner to do that,” Chairman and CEO Al Clise said Thursday.

Amazon has indicated it plans to start construction next year on the first block, between Sixth and Seventh avenues and Virginia and Lenora streets.

The company applied Wednesday for a city permit to demolish the largest building on that block, the 54-year-old Sixth Avenue Inn. The hotel closed late last month.

The other two blocks would be developed at two-year intervals, Amazon’s representatives have said.

An Amazon spokesman did not return a call or email Thursday.

Clise and Amazon reached tentative agreement on the sale in late January, and Amazon filed the first paperwork with the city for the development a few weeks later.

City planners gave their blessing to the complex last month.

Amazon has options to buy another 1½ Clise blocks just to the north, along Seventh Avenue between Blanchard and Bell streets. The company has more time to decide whether to exercise those options, Al Clise said.

But Amazon recently bought the only lot on those 1½ blocks not owned by Clise.

The $207.5 million Amazon paid Clise breaks down to about $914 per square foot. That’s about 5 percent more than the $872 per square foot GID Development of Boston paid in October for property across Westlake from the Amazon blocks, where it plans to build a 40-story apartment tower.

Clise Properties plans to reinvest the money from the sale, Al Clise said: “We’re a real-estate company, and we’re going to purchase more real estate.”

It’s looking mostly at income-producing properties, he said, but also is considering new development.

He wouldn’t specify where: “We like Seattle, but everybody likes Seattle right now.”

The company still owns more than 8 underdeveloped acres in the Denny Triangle. Its other holdings include the 34-story Westin Building at Sixth and Lenora, and the 24-story 1700 Seventh Avenue, at Seventh and Stewart Street.

Clise acknowledged that possible changes in federal tax laws next year provided an incentive to close the Amazon sale before Dec. 31. That’s been a factor in a number of big recent real-estate transactions.

The largest of all — Amazon’s $1.16 billion purchase of its leased, 11-building South Lake Union headquarters campus from Vulcan Real Estate — is slated to close Friday, a Vulcan executive has said.

Eric Pryne: or 206-464-2231