Egypt, which depends on imported food and energy, is facing a dollar shortage and mounting pressure to devalue the pound.
The central bank surprised markets when it strengthened the pound on Nov. 11 by 20 piasters against the dollar.
On Thursday, it sold 39.4 million dollars at a cut-off price of 7.7301 pounds to the dollar, unchanged from Tuesday.
The official rate is still far from the black market, which was around 8.57 pounds to the dollar on Thursday, almost unchanged from Tuesday's rate of 8.58.
The country has been starved of foreign currency since a popular uprising in 2011 ousted autocrat Hosni Mubarak and drove tourists and foreign investors away.
Egypt's reserves have tumbled from $36 billion in 2011 to$16.4 billion, and the country has been rationing dollars through weekly dollar auctions to banks, keeping the pound artificially strong.
In February, the central bank imposed capital controls, limiting dollar-denominated deposits to $50,000 a month in an attempt to fight the black market.
The move caused problems for importers, who could no longer source their foreign currency needs.