Production has ground to a halt at a major bio-fuel factory on Teesside.
Bosses at Ensus say market conditions have forced them to temporarily postpone production.
It's not known when work will start again.
The 100-strong workforce at the Ensus biofuel plant at Wilton on Teesside will keep their jobs during the halt in production.
The company operates one of the world's largest cereal grain bio-refineries. It refines wheat to produce enough biofuel to meet one third of the UK's bio-ethanol demand.
It says the current high cost of wheat, because of a poor 2012 harvest, means it's not competitive to continue making ethanol at the moment. Ensus adds that while its manufacturing costs have risen, the price of ethanol hasn't gone up enough to make production worthwhile.
Ensus says it does not know how long the pause in production will be at the moment, but it hopes market conditions will improve so that it can make the Wilton plant operational again in the near future.
Ensus - one of the UK's biggest biofuel makers - has temporarily halted production at its Wilton plant on Teesside
It says the high cost of wheat, which it processes to make biofuel, animal feed and carbon dioxide, means it's not competitive to continue production, but no staff are being laid off.