Warning that tens of thousands of jobs are at stake, governors in wind energy states Tuesday called on Congress to renew an expiring tax break.

Iowa Gov. Terry Branstad and Oregon Gov. John Kitzhaber said at a teleconference that uncertainty over the future of the wind energy production tax credit already has hurt the industry - which employs 75,000 people and drives more than $10 billion a year in economic development. Branstad and Kitzhaber lead the Governor's Wind Energy Coalition, which represents 28 states.

The credit was first signed by President George H.W. Bush and backed by a number of prominent Republicans. But legislation to renew the tax break stalled in Congress this summer amid opposition from conservative House Republicans, who argued it was wasteful spending. Republican presidential nominee Mitt Romney opposed it.

In a letter to leaders in Congress, the governors wrote that 37,000 jobs and the chance to drive $10 billion in private investment will be lost if the credit expires. They estimated the wind industry employs 75,000.

"It is time to turn the page on the recent election and work together to get Americans back to work," Kitzhaber, a Democrat, said in a statement.

Wind energy companies already have started shrinking their workforces. The Danish wind turbine manufacturer Vestas has allowed its Colorado workforce to decline by 500 jobs, and announced last week it plans to cut its global workforce by another 3,000 by the end of next year due to uncertainty over the tax credit.