Brussels, 09/03/2011 (Agence Europe) - Portugal issued a billion euros worth of two-year public debt on Wednesday 9 March for a far higher interest rate than an equivalent rollover in September (nearly 6% in March as opposed to 4% in September). Demand was 1.6 times higher than supply. The downgrading of Greece on Monday has increased Portugal's rollover costs, raising the ten-year rate to a new record high (7.6%). Similar hikes have been seen for other countries' rollover costs on the edges...