Weyerhaeuser Co. and Plum Creek Timber Co. both announced Feb. 12 that their shareholders have approved a deal in which Plum Creek will merge into Weyerhaeuser.

The union--which will retain the Weyerhaeuser name--will create a business with roughly $8.5 billion in annual sales and nearly $750 million million in net earnings.

Plum Creek brings to the deal more than 6 million acres of timberlands in 19 states while Weyerhaeuser controls nearly 7 million U.S. acres of timber as well as leases on Canadian timberlands. Both companies are based in the Seattle area. It's an all-stock transactions, with cost savings through synergies expected to amount to $100 million.