The average yields on LE4.5 billion ($738.49 million) of 91- and 266-day treasury bills fell sharply at a central bank auction on Sunday, the Ministry of Finance said. The average yield on LE1 billion of 91-day bills dropped to 12.396 per cent, its lowest since November last year, from 13.747 per cent at an auction on 9 September. The yield on LE3.5 billion of 266-day bills tumbled to 13.354 per cent, its lowest since August last year, from 15.486 at the 9 September auction. Interest rates on the Egyptian government's debt have fallen from historic highs in recent weeks as optimism grows that it will secure help for a struggling economy from the International Monetary Fund and other foreign donors. The central bank sold all the bills it had offered on behalf of the finance ministry.