This is part of an informal examination being conducted in terms of the possibility of antitrust activity.

Media reports state that the EC has sent a note to the Hollywood studios in the middle of last month asking whether they had imposed restrictive agreements in choosing between Blu-ray and the other rival format HD-DVD.

Video rental store Blockbuster recently said that it would only stock films using Blu-ray.

The two competing standards have each won exclusive support from different studios. This has causied concern that antitrust regulations may have been violated.

The Sony backed Blu-ray format has won strong support from Hollywood. Disney, Fox and Sony Pictures have released Blu-ray discs but not the competing HD DVDs. That format was developed by a consortium led by Toshiba.

Universal Studios is the only studio which releases high-definition movies exclusively on HD DVD.