European officials have denied making a ruling that scuppered a state-funded deal to rescue Northern Ireland's only air link with the US.
First Minister Arlene Foster had accused "Brussels bureaucracy" of thwarting the Executive's £9million support package for United Airlines to maintain its Belfast to Newark service.
Her DUP colleague and economy minister Simon Hamilton levelled similar criticism against the European Commission, claiming its rules on state aid torpedoed the deal.
A spokeswoman for the commission said: "To be clear, the European Commission received a complaint alleging that the measure was in breach of EU rules, which it looked into, but we did not take any decision on the matter.
"The Northern Irish authorities and United Airlines have themselves decided to end their arrangement."
United will stop the service in the new year.
On Monday, Mrs Foster told the Assembly: "I think it was worth doing, I think it was the right thing to do at the time, but unfortunately the EU did not agree with us.
"They have decided that we cannot proceed with what they call state aid and because of that, United quickly took the decision, paid back any money that they had already received and they are now going to be leaving Belfast International Airport at the beginning of January."
She added: "Of course, if we had not been in the EU, we would have been able to do it and that is the fundamental nub of this.
"I think if I were to look for a very practical expression of state aid bureaucracy, here it is."
Ulster Unionist Assembly member Steve Aiken said the Executive needed to provide clarity "as a matter of urgency" on who decided the funding was inadmissible under EU rules.
"This is absolute dynamite," he said.
"It now appears that the vital direct link to North America was pulled without a formal ruling being received from Brussels. Indeed, if a formal ruling had been received, we could probably have found ourselves in a much better position to marshal opposition to the unnamed complainant and maintain this vital strategic air link."
Mr Hamilton said the EU Commission had indicated to both his department and the airline that it viewed the funding as state aid.
He said United then announced its decision to withdraw the service before the commission commenced a formal investigation.
"The facts are straightforward," he said. "The European Commission informed United Airlines that, in its view, the support package for the Belfast-Newark service constituted state aid. That was conveyed at a meeting at which my department was represented along with United.
"The Commission was also poised to trigger a formal investigation into a complaint received about the Executive package.
"Faced with the Commission's starting viewpoint and the likelihood that this would be confirmed in the formal investigation of the complaint, United took the decision to end the service.
"I deeply regret that decision, but that does not mean we were wrong to try to save the route.
"Our critics have to decide if they are complaining about the loss of the route or our attempt to preserve it. They can't have it both ways."