Average yields on 6 and 12 months Egyptian treasury bills inched down at an auction on Thursday and the central bank sold all the bills it was offering, the Ministry of Finance said. The average yield on the 6-monthsT-bills was 14.819 per cent, down from 14.867 per cent at the last auction. The bank sold bills worth LE3.5 billion ($580.17 million). The average yield on 12-months T-bills was 15.919 per cent, down from 15.954 at the last issue on 6 March, and it sold LE3.5 billion of the bills. The central bank sells the bills on behalf of the ministry.