According to M. C. O'Brien, Inc., Karen Cohen has joined as a new associate in the commercial real estate sales and leasing department. Cohen's focus will be on sales and leasing of all types of commercial property including retail, office, and warehouse spaces. Her background includes property management, construction and retail merchandising and management. M. C. O'Brien has been in the Real Estate Business since 1909 and has extensive expertise in the Brooklyn/Queens commercial real estate markets. According to William P. O'Brien, SIOR President, and grandson of founder Michael C. O'Brien Sr., "last year was a record year for us and we believe that with Karen's unique skill set, we will be able to improve on that performance.