An American was appointed on Tuesday to oversee the renovation of the world headquarters of the United Nations, which at age 60 needs an overhaul of its organization as well as the slightly younger administrative building. Louis Frederick Reuter was appointed by U.N. Secretary-General Kofi Annan as a U.N. assistant secretary-general in charge of implementing the capital master-plan to renovate the headquarters in New York. Reuter, an architect, was an executive vice president of the New York Presbyterian Hospital until 2001. He helped rebuild the New York Weill Cornell Medical Center over the East River Drive in Manhattan, a 1-billion-dollar project. Reuter held various consulting assignments since 2001 for PricewaterhouseCoopers, an accounting firm in New York, and the Qatar Foundation for Education, Science and Community Development. The U.N. master-plan calls for spending more than 1 billion dollars to renovate the 39-floor secretariat building, the U.N. General Assembly hall and a library. The U.N. compound overlooks Manhattan's East River on a piece of land that was donated by the Rockefeller family. The United States has offered a loan of 1 billion dollars at low interests, for 30 years, for the renovation.