Ad agency Arnold Worldwide is weighing a relocation to the original Filene’s building in Boston in what would be a blockbuster deal for Downtown Crossing and efforts to revitalize the area, according to multiple industry sources.

A marquee anchor tenant like Arnold for the property known as the Burnham building could be the golden ticket project developer Millennium Partners needs to secure financing and start construction of a 625-foot, 600-unit residential skyscraper adjacent to the Burnham, sources close to the project told Banker & Tradesman. 

The 300,000-square-foot property at the corner of Washington and Summer streets is vacant and needs major renovations, but could be ready for a move-in date sometime in 2014, industry experts close to the deal told Banker & Tradesman. No other tenants are actively considering the Burnham building, sources said. Arnold currently occupies about 300,000 square feet of office space at 101 Huntington Ave.

The Burnham building opened in 1912 after being designed by eminent architect Daniel Burnham.