STAMFORD, CT-Northwestern Mutual—Stamford has signed a long-term lease with the Landis Group for approximately 20,000 square feet at 400 Atlantic St. here, GlobeSt.com has exclusively learned. The insurer is relocating to the 500,000-square-foot office property from Westport, elsewhere in Fairfield County.

A mutual company with $1.4 trillion of life insurance protection in force, Northwestern joins a tenant roster at the 15-story office tower that also includes UBS, American Express, the Santander Group and Harman Kardon. In the past few months, they've been joined by the Navigators Group and Charter Communications, both of which have relocated to 400 Atlantic.

Scott Landis, principal at the Landis Group, attributes 400 Atlantic's “rapid acceptance and leasing success” to key attributes including “headquarters-quality space, access to a diverse downtown atmosphere and numerous transportation options.” Built as Champion Paper's world headquarters, the property is located across from the Stamford train station.

In 2012, the site was named the office building of the year from the Southern Connecticut Building Owners and Managers Association in the 500,000-to one-million-square-foot, multi-tenant category. Each of the building's floors presents an opportunity for eight corner offices.