Starwood Hotels & Resorts' North American portfolio is expanding at an accelerated clip. The lodging company opened 23 new properties on the continent last year and signed 64 more, the latter representing a 23 percent year-over-year increase. "North America remains one of Starwood's most important global markets," noted Simon Turner, Starwood's president of global development, "accounting for approximately 50 percent of our global portfolio and a third of our hotel openings in 2014." The growth spurt was led by the company's select-service brands -- Four Points by Sheraton, Aloft and Element -- which accounted for 83 percent of all North America signings last year. Demand also is on the rise specifically for dual-branded Aloft and Element projects. In the upper-upscale sector, Starwood intends to open nine new properties in North America over the next three years, among its Sheraton, Westin and Le Méridien brands. Four of those hotels will fly the Sheraton flag, which is Starwood's largest development pipeline, and the biggest in Sheraton's history. Sheraton is expected to open its 500th property worldwide this year. In the luxury segment, Starwood's Luxury Collection will open three properties in the region over the next year. Major renovations are planned for a number of properties representing the company's other luxury brands, St. Regis and W.