The latest attempt by Adolph Coors ( RKY) and Molson to win shareholder approval of their $6 billion merger plan has fallen flat with Coors investors.

The brewers' latest offer will pay shareholders of Canada-based Molson a special dividend of $4.53 a share, or $5.44 Canadian, up from $2.71, or $3.26 Canadian. The offer increases the value of the deal by $532.6 million, or $640 Canadian.

In July, the companies announced plans to merge, creating the industry's fifth-largest company under the name Molson Coors. The beer industry has undergone enormous consolidation in recent years.

Overall, shareholder support has been lukewarm with some groups threatening to vote against the proposal.

In related moves late Thursday, Molson said its special meeting of shareholders scheduled for Jan. 19 will be adjourned and reconvened on Jan. 28. Coors said its stockholder meeting scheduled for Jan. 19 will be convened as planned and then immediately adjourned so it can be reconvened Feb. 1.

The Federal Trade Commission approved the merger in October.

Coors shares fell $1.82, or 2.4%, to $74.32.