Vale SA (NYSE:VALE) announced late yesterday that its board of directors has approved a $3 billion share repurchasing program for common and preferred class A shares of their respective American Depositary Receipts.The repurchased shares will be cancelled after the expiration of the program, which includes the buyback of up to 84.8 million common shares and 102.2 million preferreds, representing up to 5.9% of the total free float as of May 31, 2011.The program will be executed over a 180-day period, extended from May 31, 2011 to November 25, 2011.Shares of Vale are trading up 1.75% at $32.51.