Global management-consulting firm McKinsey & Co. announced this week a plan to relocate its lone offices in Connecticut, which are located in the south end of Stamford, to a new mixed-use development in downtown Darien.

McKinsey has signed a lease for about 12,000 square feet at 1 Market St., an under-construction building in The Corbin District that is expected to be ready for occupancy in the summer of 2026. The new offices will replace McKinsey’s current offices at 100 Washington Blvd., which is part of the Harbor Point mixed-use development. About 270 employees are based at 100 Washington Blvd., and that contingent is growing, according to McKinsey officials.

“As consultants, our colleagues require flexibility to determine where they work based on client needs — either at the client site, co-locating at our McKinsey office, or working from home,” McKinsey officials said in a written statement. “After evaluating these needs for both colleagues and clients, we have determined that our growth is best served by moving to a new location in Darien. We’re eager to further develop our presence in Connecticut with this move.

McKinsey’s statement also referenced temporary offices that the firm plans to move into in the fourth quarter of this year. In response to an inquiry from CT Insider, a spokesperson for McKinsey said that all of the Stamford-based employees would move to the temporary offices, which the firm would use until its offices at 1 Market St., were ready for occupancy. The spokesperson did not immediately respond to a follow-up question from CT Insider about the location of the temporary offices.

At 1 Market St., McKinsey will take space in a building that will be located on a new side street and house approximately 95,000 square feet of offices. About 75 percent of the office space has been pre-leased, with professional-services firm Aon, wealth-and-asset manager Janney Montgomery Scott, investment advisory firm Crestwood Advisors and alternative-investment management firm Balance Point Capital also having signed leases, according to David Genovese, founder and CEO of Baywater Properties, the developer of The Corbin District. Another firm is expected to sign a lease soon at 1 Market St., Genovese said.

“We’re extremely pleased with the market’s response to the development,” Genovese said in an interview this week. “We have never seen this strong of a response, pre-completion. Darien, in our opinion, is clearly benefiting from some of the after-effects of the pandemic in that people want higher-quality spaces that are within walking district to the train and are in amenitized, pedestrian-friendly locations.”

In addition to the office space, 1 Market St., will accommodate about 25,000 square feet on its first floor. Corsica, a new restaurant concept from the team behind Barcelona Wine Bar, home goods retailer French Presse, and yoga studio YogaSpark have signed leases on the first level, according to Genovese.

“What would make an office employee be more excited to be at work or in the area?” Genovese said. “The idea being, if we got the first floor right, it would drive demand for the upper floors.”

The in-state operations of McKinsey highlight the large presence of the professional-services sector in southwestern Connecticut. Stamford, the state’s second-most-populous city, is an industry hub, with each of the “Big Four” professional-services firms — Deloitte, EY, KPMG and PwC — having offices in the city.