CHESAPEAKE, Va. — Family Dollar is rejecting Dollar General’s latest acquisition offer, and Dollar Tree says it will now divest as many stores as needed to get antitrust clearance for its deal to buy Family Dollar.

Family Dollar rejected an earlier offer of nearly $9 billion from Dollar General, with the Goodlettsville, Tenn., discounter then boosting its bid to $9.1 billion. Dollar General — the nation’s biggest dollar-store chain — had also revised its proposal to increase the number of stores it would be willing to divest and to include a $500 million reverse break-up fee to Family Dollar if the deal hit antitrust roadblocks.