An export tax will drop to zero under a complicated formula in the softwood lumber agreement. ((Richard Lam/Canadian Press))

B.C. lumber producers are getting a double dose of good news — prices are rising and the tax they pay to ship their product to the U.S. is disappearing on June 1.

Under the Softwood Lumber Agreement signed with the U.S. in 2006, softwood lumber taxes are tied to the average price of lumber, and when the price goes up, the tax comes down.

Prices have now risen so much the tax will be eliminated entirely, at least for the month of June.

"In two months, the export tax has dropped from 15 per cent to zero because of higher lumber prices," said Forests and Range Minister Pat Bell.

"While prices have softened over the last week, and will likely continue to fluctuate, no export tax during June on lumber shipments to the U.S. means companies will have more cash available for re-investing in their mills."

The tax will be reinstated if prices fall again.

The U.S. is B.C.'s largest market for softwood lumber, followed by China and Japan.