Egypt's pound slid by half a per cent on Sunday at the central bank's fifth auction of foreign currency, with all $60 million on offer sold to banks at a cut-off price of LE6.4185, the central bank said.

Thursday's cut-off price was LE6.3860 to the dollar. The weakening is in line with the central bank's interbank trading band, which it narrowed on Wednesday to plus or minus 0.5 per cent from the previous 1.0 per cent.

The central bank has sold $360 million and the currency has lost more than 4 per cent of its value against the dollar since it began a new currency regime on 30 December to slow the depletion of the country's foreign reserves, which the bank said had fallen to a critical level.

Egypt's foreign reserves dropped by $21 million in December to reach $15.014 billion, the Central Bank announced on Sunday.