LAS VEGAS— The W Las Vegas mixed-use project slated for almost 50 acres along Harmon Avenue here was canceled Friday after minority partner Starwood Hotels & Resorts Worldwide pulled out of the project. In a brief e-mailed statement, the Edge Group said its partnership with Starwood is scheduled to end and the project “could not overcome numerous significant challenges.” W Las Vegas was first proposed in 2005 for 22 acres on the northeast corner of Harmon Avenue and Koval Lane. It was billed as a $2.5-billion mixed-use project with 3,000 hotel condominium units, 10 restaurants and nightclubs, a 75,000-square-foot casino, 300,000 square feet of convention and meeting space, a Fred Segal fashion emporium and a spa. It was to open in 2008. The Edge Group had bought the land from homebuilder D.R. Horton for $108 million. The W Las Vegas was to neighbor the 4,000-unit hotel-condominium project, Las Ramblas, which was tied to actor George Clooney and nightclub magnate Rande Gerber. But poor unit sales forced Las Ramblas cancellation and it sold 25 acres and entitlements to the Edge Group for $202 million in June 2006. A Starwood pullout had been rumored since late last year, but Edge officials maintained in the past few months that the project was proceeding and cited a $10-million investment by Starwood last year as proof. Edge spokeswoman Maggie Feldman said company officials could not comment further now but added that the group is selling assets, including the land.