Egypt's central bank sold more 91-day treasury bills than originally offered at an auction on Sunday but trimmed the amount 266-day T-bills sold, the Finance Ministry said on its website. The bank sold 3 billion Egyptian pounds of 91-day bills compared to the 2 billion it offered, with the average yield remaining steady from last week at 13.95 per cent. It sold only 1 billion pounds of 266-day T-bills, short of the 3.5 billion pounds it had offered, with the average yield rising to 15.26 per cent from 15.144 per cent at the last issue on Dec 13. The bank sells T-bills on behalf of the Finance Ministry.