Haug says Mercedes supplying fourth team 'difficult'

Norbert Haug has played down reports that Mercedes could be looking to add a fourth team to its F1 engine programme for 2011.

It emerged in recent days that the German marque's board of directors met and discussed whether it should supply the powerful 2.4 litre V8 to another team.

Mercedes already powers its own Brackley based team as well as McLaren and Force India, but it is known that Red Bull is open to moving from the Renault stable.