Airbus has disclosed that it is facing a separate probe into business irregularities, centred on US regulatory compliance on defence contracts.
The airframer had already been dealing with investigations from the UK's Serious Fraud office and a related probe involving the French Parquet National Financier.
But during a review of US regulatory compliance procedures, it says it has discovered "certain inaccuracies" regarding filings to the US Department of State.
These relate to the US International Traffic in Arms Regulations. The section of the ITAR regulation in question, known as Part 130, deals with disclosure of fees, commissions and political contributions.
Airbus has not elaborated on the specific nature of the investigation but chief financial officer Harald Wilhelm says that it is a "separate review" to that being undertaken by the UK and French authorities.
He says that ITAR-related applications need to be made for defence contracts and to obtain export licences, and that Airbus found "some shortcomings" in the Part 130 reporting.
Wilhelm stresses that Airbus is "fully co-operating" with regulatory authorities in both the US and European proceedings.
Airbus says the likelihood, or scale, of any potential financial penalty cannot yet be determined in either case.