LAS VEGAS, April 25, 2013 /PRNewswire/ -- MGM Resorts International (NYSE: MGM) properties have been awarded a new designation by TripAdvisor ®, the world's largest travel website, that helps identify the most environmentally friendly hotels. Twelve MGM Resorts properties on the Las Vegas Strip were accepted into the new TripAdvisor GreenLeaders™ program. The program considers a property's holistic approach to "green" practices and ranks them based on four levels of participation - Bronze, Silver, Gold or Platinum. ARIA Resort & Casino and Vdara Hotel & Spa each received a Platinum designation – denoting the highest level of environmental responsibility - an achievement earned by less than 10 percent of participants. Gold designations went to MGM Grand Las Vegas, The Mirage, New York-New York, The Signature at MGM Grand, Bellagio, Monte Carlo and Mandalay Bay. Excalibur and Luxor received Silver designations. Circus Circus Las Vegas earned Bronze. "The new TripAdvisor ranking system is a powerful tool for consumers to refer to when they are selecting a hotel," said MGM Resorts Chief Sustainability Officer Cindy Ortega. "We know very well that our guests vote with their feet, and, increasingly, guests are placing environmental responsibility high on their priority lists when making important travel decisions." TripAdvisor lauded MGM Resorts for its sustainability practices and procedures. "MGM Resorts has an impressive number of properties that are dedicated to educating their guests and potential guests about the sustainability aspects of Las Vegas," said Jenny Rushmore, director of responsible travel for TripAdvisor. "It is clear that MGM Resorts has demonstrated that the company is truly committed to reducing their resorts' environmental impacts and increasing the transparency of its 'green' programs with guests." TripAdvisor has launched the GreenLeaders program with more than 1,000 properties, comprised of independent hotels to multinational brands. Web surfers can refine their search on TripAdvisor.com to hotels that hold the "green" designation, and a view of each hotel's sustainability features.