Foreign buyers of U.S. Treasury debt increased their holdings to a record in December, even though the two biggest holders of U.S. government securities - China and Japan - reduced their shares. The Treasury Department said Tuesday that foreign holdings rose 1.4 percent in December to $5.79 trillion, beating the old record set last March of $5.73 trillion. Foreign holdings had fallen from April through July before rising again in August. China, the largest foreign holder of Treasury debt, reduced its holdings 3.6 percent to $1.27 trillion in December. Japan, the second-biggest holder, reduced its holdings 0.3 percent to $1.18 trillion.