The deal between Boeing and Embraer has been hit with another delay as the European antitrust regulators have been forced to stop its review of the deal.
The agreement will see Boeing take an 80% controlling stake in the commercial airline and services business of Brazilian planemaker Embraer.
However, regulators have cited the fact that insufficient documentation has been provided as the reason the investigation has come to a halt and will not be restarted until such time as it has been provided with all the information it has requested.
A spokeswoman for the regulator said: "Parties must supply the necessary information for the investigation in a timely fashion.
“Failure to do so will lead the commission to stop the clock.”
A Boeing representative said the two firms “continue to co-operate with the European Commission as they assess our transaction and look forward to a positive resolution.”
Under the EU merger regulation, the commission is concerned that the transaction may reduce competition as regards commercial aircraft.
The deal had originally expected to close by the end of 2019.
The commission is expected to make a decision by 20 Feb 2020.