SAN ANTONIO— Four new Staybridge Suites properties totaling about 500 rooms are in the works here. When completed, the projects will triple Staybridge Suites’ presence in San Antonio. The projects include the $15-million, 12-story, 138-suite Staybridge that SSG Hotel is expected to open in summer 2007; the $10-million, five-story, 120-suite Staybridge that Montex Real Estate, Co., LLC will open in spring 2008; the four-story, 120-suite Staybridge that La Cantera Hospitality LLC will open in spring 2008; and the $15-million, 10-story, 120-suite Staybridge that Vaquero Development Co. will open in early 2009.