DOVER, Del. — A Delaware judge says stockholders of Family Dollar Stores Inc. can vote on proposed $8.5 billion acquisition by Chesapeake, Virginia-based Dollar Tree Inc.

Family Dollar shareholders are to vote on the acquisition Tuesday. But some Family Dollar shareholders want the vote postponed until the board reviews a deal with Dollar General Corp., which has also bid for Matthews, North Carolina-based Family Dollar.

The judge ruled Friday that Family Dollar's board acted reasonably in not negotiating with Dollar General, which is based in Goodlettsville, Tennessee, because of antitrust risks and uncertainty that regulators would approve the deal.

Family Dollar and Dollar General have similar business models, selling items at prices generally ranging from $1 to $10, while Dollar Tree prices all items at $1 or less.