MEXICO CITY – Mexico's central bank has auctioned off US$3 billion in foreign reserves to prop up the falling peso.

That's Mexico's largest auction yet in response to the global financial crisis. The bank auctioned off 2.5 billion on Wednesday and Thursday.

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

On Friday morning, after the auction, it was trading at 13.4.