Artikel 6

1. A Contracting State cannot claim immunity from the jurisdiction of a court of another Contracting State if it participates with one or more private persons in a company, association or other legal entity having its seat, registered office or principal place of business on the territory of the State of the forum, and the proceedings concern the relationship, in matters arising out of that participation, between the State on the one hand and the entity or any other participant on the other hand.
2. Paragraph 1 shall not apply if it is otherwise agreed in writing.