F5 Networks, Inc. a computer and data processing company, signed a 14.5-year office lease for 515,000 square feet at the in-development office tower rising at 801 5th Ave. in Seattle, WA.

The 48-story, 528,000-square-foot office building will sit atop the 19-story SLS Hotel with F5 Networks occupying floors 20 thru 48. Construction is expected to be completed in June 2017.

Craig Kinzer, Adam Brenneman and Shelley Gill of Kinzer Partners represented…