Sources have confirmed to CBC News that a deal to sell the Come By Chance oil refinery in Placentia Bay has collapsed, and that the idled facility will close permanently.
Workers received notice from North Atlantic Refining on Monday, and an all-staff meeting is planned for Tuesday morning.
The union local has declined comment.
It's the worst possible scenario for a refinery that appeared to be on the upswing prior to the global pandemic, which forced the owners to stop refining fuels in March.
There was also hope that a proposed deal with Irving Oil would give the aging facility new life, but that prospect now appears to have been dashed.
Insiders say the closure could do away with 500 direct jobs, and mean less work for dozens of contract employees.
"The company will not be providing comment on internal, confidential matters at this time," North Atlantic Refining said in a statement Monday evening.
In the past, the refinery has contributed to as much as five per cent of the province's economy.
Early reaction coming provincially and federally
In a tweet published Monday night, Premier Andrew Furey said discussions with the owner of the refinery are ongoing, and that the owner "continues to work on its options."
"I recognize that this is an unsettling time for the hard-working people at the refinery in Come by Chance," Furey wrote. "The refinery is an asset to this province, and one our government will maximize."
In a statement to CBC News, Industry, Energy and Technology Minister Andrew Parsons called this a difficult and uncertain time for the province.
"The owner Silverpeak has invested substantially in the refinery which is an asset for the province," Parsons wrote. "Silverpeak continues to work on its options. We have been talking with them regularly and we will support them as we can. The refinery is important to the people of the province."
Federal Conservative Party of Canada Leader Erin O'Toole also issued posts on social media about the closure, saying "Terrible news at anytime of year, but Thanksgiving will be all the more challenging for too many homes."