Playa de Sol Group signed a long-term master affiliation agreement with Interval International that covers the companies' four existing resorts in Mexico and any future properties….October has become the month for resort investment conferences. The newest one is the Leisure Real Estate Developers Forum sponsored by Cendant Corp. It will be held Oct. 24-26 at the Chicago Hilton. Go to www.lredf.com for more information. On Oct. 17-9, the 7th annual Timeshare & Resort Investment Conference will convene at the Peabody Orlando. For information on the event, go to www.timeshareinvestment.com….Intrawest Corp. entered into an agreement with Hilton Grand Vacations Co. that will provide reciprocal vacation privileges to members of both companies….The third of a planned 14 timeshare buildings opened in late June at the Resort at Split Rock in the western Pocono Mountains of Pennsylvania. The new building has 24 two-bedroom suites….Carnival Cruise Lines gave its Pinnacle Award for the sixth consecutive year to Interval Travel. The award recognizes high sales achievement.