Mark A. Arena joined AMR Commercial LLC as vice president. Arena represents both landlords and tenants throughout Montgomery County. Arena has over 18 years of experience in the commercial real estate industry. Prior to joining AMR Commercial, Arena served as senior vice president of operations at Guardian Realty Management Inc. for 14 years. Arena was responsible for directing all day-to-day operations including leasing, property management and administration. He has negotiated numerous leases with such tenants as the National Institute of Health, Merrill Lynch, Manugistics and Kaiser Permanente. From 1984 to 1988, Arena was vice president and controller of the Shopping Center Division for Franklin Properties, a subsidiary of the B.F. Saul Companies.