*ECONOMY IN U.S. GREW 4% IN SECOND QUARTER VS. 3% ESTIMATE *GDP IN U.S. SHRANK 2.1% IN 1Q, REVISED FROM 2.9% DROP*ECONOMY IN U.S. GREW 4% IN SECOND QUARTER VS. 3% ESTIMATE *ECONOMY IN U.S. GREW 4% IN SECOND QUARTER VS. 3% ESTIMATE