Family Dollar Stores rejected Dollar General Corp's $9.1 billion sweetened takeover offer, saying it was not reasonably likely to be completed on the terms proposed.br Family Dollar Chief Executive Howard Levine said in a statement. "There is a very real and material risk that the transaction proposed by Dollar General would fail to close, after a lengthy and disruptive review process,"br Family Dollar said it would stick with an $8.5 billion cash-and-stock offer from Dollar Tree .