In a letter sent to Congressional leaders, 369 groups and companies - including the American Wind Energy Association, the National Association of Manufacturers and the United Steelworkers - said the looming expiration is already beginning to impact the sector.
"Investments are stalling now and will continue to stall, with corresponding job losses, until a bill to extend the PTC is passed," they write.
The plea comes just three days after a coalition of 23 state governors sent their own letter endorsing the bill. This was introduced earlier this month by Representatives Dave Reichert, a Republican from Washington State, and Earl Blumenauer, a Democrat from Oregon.
"If the tax credit is allowed to expire at the end of 2012, there will be negative impacts on the high-tech manufacturing jobs that the industry has brought to or created in our states," the governors warn.