The central bank trimmed its view further for the 2012 trade surplus to $2.2 billion, from an estimate of $6.7 billion earlier this year, the Peruvian central bank's head of economic studies Adrian Armas said in a conference call.

Peru is a top producer of gold, silver, copper and zinc, and its mineral sales make up 60 percent of export earnings. But its traditional exports have suffered this year from weaker demand abroad.

August is the fourth month this year Peru has posted a deficit, and strong domestic demand is now powering Peru's solid growth rates.

Armas said prices for minerals recovered slightly in August compared to July, when Peru posted a deficit of $272 million, helping August exports surpass July's by $3.7 billion.

Peru is on track to post growth of 6 percent in 2012, likely the fastest paced economy in South America.

Peru's potential growth rate, the maximum rate the economy can expand without provoking excessive inflation, is normally seen around 6 percent or 6.5 percent.

The central bank held its benchmark interest rate unchanged at 4.25 percent for the 17th month in a row on Thursday.