The French architect Jean Nouvel has been selected to design a high-rise building that will strikingly alter the skyline in La Défense business district on the outskirts of Paris, officials announced on Tuesday. His project was chosen from among those of five finalists, among them Norman Foster and Daniel Libeskind. The building, dubbed the Signal Tower, is part of an ambitious plan to revitalize La Défense that was conceived in 2006 when Nicolas Sarkozy, who is now France’s president, led a public body dedicated to that goal. Patrick Devedjian, who succeeded him, said the tower would be the “most important architectural act since the Eiffel Tower.” Comprising four segments that resemble stacked cubes, the tower will have apartments on the upper floors, as well as a hotel, offices and a business plaza. (Above, an artist’s rendering of an interior view, and, right, of the tower, shown with the Grande Arche.) It is to be completed by 2015. Mr. Nouvel, who captured the Pritzker Prize, architecture’s top honor, this year, also designed the Quai Branly Museum in Paris, which opened in 2006, and is at work on a satellite of the Louvre Museum in Abu Dhabi in the United Arab Emirates.