Italian borrowing costs dropped considerably in a pair of bond sales that easily raised €10.5 billion ($15.15 billion), helped by the European Central Bank's program to buy peripheral bonds. Yields on 6-month bonds dropped to 2.14 percent, from 2.269 percent last month. The auction Friday raised €8.5 billion and was oversubscribed by 1.66 times, compared with 1.56 percent last month. Borrowing costs for 24-month bonds dropped to 3.408 percent, from 4.038 percent last month.Italian yields have eased since the ECB began buying Italian and Spanish bonds Aug. 8 in an effort to stem the worsening debt crisis. Six-month yields peaked at 2.8 percent, while 24-month yields reached a high of 4.5 percent.