Article 6 Brussels Convention 72/454/EEC

A person domiciled in a Contracting State may also be sued:

1. where he is one of a number of defendants, in the courts for the place where any one of them is domiciled;

2. as a third party in an action on a warranty or guarantee or in any other third party proceedings, in the court seised of the original proceedings, unless these were instituted solely with the object of removing him from the jurisdiction of the court which would be competent in his case;

3. on a counter-claim arising from the same contract or facts on which the original claimwas based, in the court in which the original claim is pending;

4. in matters relating to a contract, if the action may be combined with an action against the same defendant in matters relating to rights in rem in immovable property, in the court of the Contracting State in which the property is situated.