Apple is being threatened with having its stock de-listed by the Nasdaq index as a result of its late filing of regulatory documents following the company's discovery of "irregularities" regarding stock option grants to senior executives going back to September 2000.

The company on Friday received a letter from Nasdaq warning of the potential for de-listing. Apple has responded to the warning, filing a demand for a hearing before the Nasdaq Listing Qualifications Panel.

"As anticipated, the letter was issued in accordance with NASDAQ procedures due to the delayed filing of the Company's Form 10-Q for the quarter ended July 1, 2006," Apple said.

Company spokesperson Katie Cotton told AFP: "This is a matter of procedure when you delay a filing. We are going to file the Form 10-Q following completion of our internal investigation."

If nothing else, the filing of the demand for a hearing will buy Apple two or three more months of trading of its stock on Nasdaq (until the hearing takes place), and if the hearing succeeds then the threat will be removed.

In its defence, Apple points to its 29 June 2006 statement that: "An internal investigation discovered irregularities related to the issuance of certain stock option grants made by the Company between 1997 and 2001," which it told the SEC about.

Apple says it's "focused on resolving these issues as quickly as possible and plans to file its Form 10-Q following completion of the independent investigation by the special committee of Apple's outside directors."

Last week it was revealed that many of Apple's senior executives have been hiring counsel to represent them in the investigation, with The Street reporting that during the period between April 2000 to August 2001, Apple's didn't have a compensation committee. At that time compensation decisions were made by Apple's senior board.

Apple shares slid 8 cents on the Nasdaq de-listing threat.