Celgene Corp., of Summit, N.J., said the board authorized the repurchase of up to an additional $3 billion of the company's common stock. The open-ended program is effective immediately. Celgene now has a total of about $5.3 billion available from previous authorizations plus the new authorization. Since 2009, Celgene has returned about $15.2 billion to shareholders through the repurchase program, the company said.