Mexico's central bank has auctioned off another US$3 billion in foreign reserves, its third auction of the day in an increasingly aggressive bid to push the peso stronger. In all, the bank sold off $6.4 billion.

The first auction was for $3 billion dollars. The second was for $400 million. After the bank auctioned off another $3 billion late Friday morning at an average of 12.8 pesos to the dollar, the peso was still trading at around 13 to the dollar.

The peso began its steep fall Wednesday morning, when it dropped to a record of below 14 against the U.S. dollar. It has recovered at times to just above 12 to the dollar.