The United Nations’ decision to lease 460,000 square feet of space in Midtown Manhattan could be a prelude to something even bigger—a major commitment to a proposed office tower near U.N. headquarters. The U.N. disclosed yesterday that it is leasing the space at 380 Madison Ave., a Midtown office tower owned by developer Sheldon Solow, according to a report by Charles Bagli in the New York Times. The temporary space will house much of the U.N.’s staff during a five-year, $2 billion overhaul of the world body’s aging buildings on the East River. A Solow representative could not be reached by today’s deadline, but the developer wants to entice the U.N. to a 47-office tower he is planning. That tower is part of a controversial $4 billion proposal awaiting approval by the New York City Council. In all, Solow wants to build upwards of 6 million square feet, including six residential towers and an office tower on the 9-acre site formerly occupied by Con Edison, New York City’s electric utility. If it wins approval, the project’s approximately 4,000 residential units would make it the city’s biggest residential development and one of its largest-ever developments overall. The proposed heights of the towers, which would range up to about 60 stories, have generated opposition from community groups and city council members. Those critics want Solow to scale back the tower heights. As the New York Sun’s Peter Kiefer reported Thursday, unless the project wins approval from a key city council committee by next Wednesday, Solow may have to restart the approval process. A coalition of public officials and community groups are also calling for creation of a park as part of the site’s redevelopment, as reported on line by CPN on Feb. 21. As Solow’s redevelopment plan awaits city action, the U.N. is moving forward with its renovation program. In May, the U.N. will start construction of a temporary building that will house meetings for the General Assembly, Security Council, and other agencies, Michael Alderstein, executive director of the renovation project, said yesterday. The building, which will also provide office space, will take shape on a lawn north of the complex.