Campeau offered to sweeten its offer for Allied.

The Canadian real estate developer said its proposal to increase the offer to Allied Stores’ stockholders to $66 a share from $58 was conditioned on Allied’s board supporting the takeover bid. The total value of Campeau Corp.’s new offer would be $3.5 billion, up 13% from the $3.1 billion offer now before shareholders. Allied’s stock jumped $2.75 a share to close at $63.75 in New York Stock Exchange composite trading.