The average yield at an auction on Sunday of Egyptian 273-day treasury bills rose and the central bank sold the amount it originally offered, the Ministry of Finance said on its website. The average yield edged high to 15.859 per cent from 15.825 per cent at the last issue on May 29. The bank sold LE3 billion of 273-day T-bills, the same amount it had offered. The central bank sells the bills on behalf of the Finance Ministry.