The central bank had kept the pound at 7.5301 for five months until July, when it allowed it to slide to 7.6301.
On July 5 the bank let it slip a further 0.10 pounds.
Allowing the pound to weaken in a controlled way could boost exports and attract investment but it also raises Egypt's already-large bill for imported fuel and food staples.
Egypt has sought to tame a once-thriving currency black market with measures such as a cap on dollar-denominated bank deposits.
In January, the central bank gave banks permission to trade dollars up to 0.10 pounds above or below the official rate, with currency exchange bureaux allowed to trade at 0.15 pounds above or bellow the official rate.
One trader at an exchange bureau said the pound was changing hands at 8.04 pounds per dollar and another said it was changing at 8.05 pounds per dollar, unchanged from Sunday's rates.