The average yield on 266-day Egyptian treasury bills inched down at an auction on Sunday and the central bank sold all the bills it was offering, the Finance Ministry said. The average yield on the T-bills was 15.912 per cent, down from 15.923 per cent at the last issue on 14 Febuary, the ministry said. The bank sold bills worth LE3.5 billion ($579.9 million). The central bank sells the bills on behalf of the Finance Ministry.