Nasdaq this month notified a Colorado company that it may be delisted from the exchange because its external auditors provided no opinion about management’s internal control over financial reporting—the first time that delisting has been threatened for such a “disclaimed opinion.”

Advanced Energy Industries, a technology company based in Fort Collins, Colo., revealed the delisting letter from Nasdaq in a press release dated May 9. Advanced Energy said it believes that the inclusion of the independent auditor’s report in the Form 10-K complied with the law, even though the auditor’s report expressed no opinion.