Article 8

A person domiciled in a Member 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, provided the claims are so closely connected that it is expedient to hear and determine them together to avoid the risk of irreconcilable judgments resulting from separate proceedings;

(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 claim was 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 Member State in which the property is situated.