The courts of a Member State whose law had been chosen by the deceased pursuant to Article 22 shall have jurisdiction to rule on the succession if:

1. (a)

   a court previously seised has declined jurisdiction in the same case pursuant to Article 6;

2. (b)

   the parties to the proceedings have agreed, in accordance with Article 5, to confer jurisdiction on a court or the courts of that Member State; or

3. (c)

   the parties to the proceedings have expressly accepted the jurisdiction of the court seised.