answers: Qatari Diar
context: the architect for a U.S. embassy must be an American firm with "numerous security clearances". In November 2009, the U.S. government conditionally agreed to sell the lease of the Grosvenor Square Chancery Building to Qatari real-estate investment firm Qatari Diar, which in 2007 purchased the Chelsea Barracks. Though the price was undisclosed, the lease's worth was estimated at £500 million in July 2000. The development value of the property was reduced when the building was given Grade II listed status, requiring developers to maintain its current design. The building is now one of Mayfair's 238 listed buildings and monuments. In </s> buildings on the Place de la Concorde, as required by French law. The so-called "Talleyrand building" (Hôtel de Talleyrand) at 2 rue Saint-Florentin formerly housed the American Embassy Consular Services, Public and Cultural Affairs offices, several other government agencies, and the George C. Marshall Center. Most of these offices were subsequently moved to the chancery building. Constructed in 1769 as a private residence, the property was acquired in 1812 by Charles Maurice de Talleyrand, who owned it until his death in 1838. It was then purchased by the banker James Mayer de Rothschild, whose family owned it for over a </s> was first situated in Great Cumberland Place, later moving to Piccadilly, 98 Portland Place (1863–1866), and 123 Victoria Street in Westminster (1883–1893). The legation was upgraded to an embassy in 1893 and remained at Victoria Street until 1912, when it moved to 4 Grosvenor Gardens. In 1938, the embassy was moved to 1 Grosvenor Square (which later housed part of the Canadian High Commission). During this time, Grosvenor Square began to accommodate many U.S. government offices, including the headquarters of General Dwight D. Eisenhower and the European headquarters of the United States Navy. Following World War II, the Duke of
question: who bought the old american embassy in london