Portugal's borrowing costs drop as the Portuguese Treasury sold 1 billion euros of three-month bonds, where the average yields on those bonds totaled 4.873% compared with a previous of 4.895 recorded in November. Demand was 2.0 times the quantity offered, compared with 2.4 times recorded in November. The Treasury sales target was in the range of 1.00-1.25 billion euros, according to IGCP.