NEW YORK(TheStreet) - Grocer Winn-Dixie Stores said it will be sold to rival supermarket chain BI-LO in a buyout that values the company at $560 million, or $9.50 a share, a 75% premium to Friday's close. With Winn Dixie, BI-LO's merged supermarket business will contain 690 stores in the southeast, which employ over 63,000 employees.