Boeing is returning to downtown Seattle after an absence of many decades.

The company's commercial airplanes division announced Thursday that it has leased the top two floors of the Russell Investments Center, once known as the WaMu Center.

About 80 employees will have offices there beginning next spring.

The company said in a statement that it's establishing the downtown office in part because it has outgrown its office space in Renton. The new office's central location will be useful to employees who must travel between its Everett and Renton plants, it said.

What's more, Boeing added, the office "will improve the experience for our customers who typically stay downtown when doing business in Puget Sound."

The last time Boeing rented office space in downtown Seattle in the 1970s, a spokesman said.

Another spokesman, Mark Hooper, said the Russell center offices won't be considered Boeing Commercial Airplanes' headquarters, although division CEO Jim Albaugh will have an office there as he does in the Longacres complex in Renton and in Everett.

"It's basically just another office for us," Hooper said. "BCA headquarters in Puget Sound does not reside in one building."

The company is leasing 45,000 square feet — all of floors 41 and 42, and part of floor 17.

The Boeing lease is the latest coup for the Russell center's owner, insurance giant Northwestern Mutual, which bought the tower — once Washington Mutual's headquarters — for a bargain price in September 2009 when it was almost entirely empty.

Since then it has signed an all-star list of tenants, starting with its subsidiary, Russell Investments, lured from Tacoma. Other big tenants include Nordstrom, biotech Dendreon and online real-estate marketplace Zillow.

With Boeing, the 890,000-square-foot tower now is 97 percent leased, according to information from commercial real-estate database Officespace.com. The 40th floor is the only one that remains completely vacant.

Filling the Russell center gives downtown a psychological boost, said Kate Joncas, president of the Downtown Seattle Association: "It was just heartbreaking when Washington Mutual moved out."

And having Boeing, one of the region's premier companies, establish a downtown presence is important symbolically, she added.

The Russell center's success underscores how much the downtown office market has rebounded, Jason Flynn, managing director at real-estate services firm Eastdil Secured, said at an industry breakfast in Seattle Wednesday — before Boeing's announcement.

"I think people were wondering if it was ever going to be leased up," he said. "It's phenomenal what's happened there over the last two years."

Eric Pryne: epryne@seattletimes.com or 206-464-2231

Information in this article, originally published Nov. 17, 2011, was corrected Nov. 21, 2011. A previous version of this story, relying on information from Boeing, said the company hadn't had a presence downtown since World War Two. Boeing says it rented office space in downtown Seattle in the 1970s.