Dollar General Corp. will need to address antitrust concerns if it wants to acquire Family Dollar Stores Inc. (NYSE:FDO), analysts say. On Thursday, Family Dollar board unanimously rejected an unsolicited, all-cash bid of $9.7 billion from Dollar General, citing those regulatory concerns. The discount retailer also said it did not want to jeopardize an existing $8.5 billion deal with Dollar Tree Inc.(NASDAQ:DLTR).