The central bank sold $38.3 million to banks at the auction, with a cut-off price of 6.9505 pounds to the dollar, compared with 6.9506 pounds at Monday's auction.
On the black market, the dollar was offered at around 7.37 pounds on Tuesday, a market participant said.
The pound has been under pressure during three years of political turmoil.
Egypt's foreign currency reserves stood at about $17.3 billion pounds in February, down from $36 billion before the uprising that led to President Hosni Mubarak's downfall in 2011.
The central bank introduced dollar currency sales over a year ago.
In January, it held a $1.5 billion exceptional auction, its largest ever, to restock the market with dollars and curb unofficial currency trading.