Envirosell, the New York-based consumer behavior research and consulting firm founded by Paco Underhill, opened an office in Istanbul, it said.

The firm, whose clients include The Gap (GPS), Adidas, BP Plc (BP/) and Wal-Mart Stores Inc. (WMT), will offer marketing and sales consultancy to companies in Turkey, the company said in an e-mailed statement today.

To contact the reporter on this story: Ercan Ersoy in Istanbul at eersoy@bloomberg.net

To contact the editor responsible for this story: Benedikt Kammel at bkammel@bloomberg.net