CHICAGO—As the openings of the city's latest office towers draw near, competition for tenants is increasing in the downtown office market, especially for firms in the West Loop that can pay for the best class A spaces. But Mayer Brown, LLP has decided to sign a lease extension with Irvine Co. Office Properties for 265,000 square feet at its 71 S. Wacker Dr. The law firm has been there since the modernist tower opened in 2005.

"We did a thorough investigation of other potential spaces, including potential new buildings, with the assistance of our broker, CBRE," Rebecca Eisner, partner-in-charge of Mayer Brown's Chicago office," tells GlobeSt.com. "In the end, we concluded that it would be most advantageous for us to remain at 71 S. Wacker, and to undertake some changes to make more efficient use of our space."

The building is currently 98% leased. Other longtime tenants include the regional offices for Citizens Bank, Piper Jaffray, Legal & General, Towers Watson and Milliman. It was designed by noted architect Henry Cobb of Pei Cobb Freed & Partners and features an elliptical design, which provides customers with setbacks and more expansive views than found in conventional skyscrapers. The building includes a three-story glass lobby with a bamboo grove, a public garden and has a LEED Platinum certification.