SEATTLE, Washington -- Shareholders of Weyerhaeuser and Plum Creek Timber approved their planned merger, both companies have announced.

Plum Creek said 99 percent of the shares voted were in favor, representing about 70 percent of the shares outstanding. Weyerhaeuser said 98 percent of the voted shares supported the deal, but gave no other details.

The merger plan, announced in November, calls for each Plum Creek share to be converted into 1.60 shares of Weyerhaeuser. The deal is expected to close before March 8 so Plum Creek shareholders become Weyerhaeuser shareholders in time to qualify for the latter's upcoming cash dividend, payable March 18.