The parties are expected to deliver those comments by Wednesday, after missing a Monday deadline. The late comments are not expected to affect the outcome of the proceeding.
A representative for the European Competition Commission declined to comment on the delay requests.
The Competition Commission is investigating whether Microsoft used its market dominance in desktop operating systems to unfairly gain share in the server market. In August, the regulatory body extended its probe to include streaming media software.
A ruling is expected sometime in the next few months, and it could include stiff sanctions against Microsoft. The European Commission has the authority to fine the software giant up to 10 percent of its annual revenue, or about $2.5 billion.
In December, Microsoft passed on a two-day hearing regarding the investigation, publicly calling on the European Commission to consider settling the case as did the attorneys general for the U.S. Justice Department and nine of 18 states.
In a related matter, U.S. District Judge Colleen Kollar-Kotelly on Monday rejected a Microsoft request to extend a scheduled March remedy hearing for its antitrust trial. Microsoft had argued the nine litigating states were trying to expand the scope of the case, necessitating a delay. Kollar-Kotelly rejected the request.