Article 57(2)(a) of the Convention of 27 September 1968 on Jurisdiction and the Enforcement of Judgments in Civil and Commercial Matters, as amended by the Convention of 9 October 1978 on the Accession of the Kingdom of Denmark, Ireland and the United Kingdom of Great Britain and Northern Ireland, by the Convention of 25 October 1982 on the Accession of the Hellenic Republic, by the Convention of 26 May 1989 on the Accession of the Kingdom of Spain and the Portuguese Republic and by the Convention of 29 November 1996 on the Accession of the Republic of Austria, the Republic of Finland and the Kingdom of Sweden, should be interpreted as meaning that the court of a Contracting State in which a defendant domiciled in another Contracting State is sued may derive its jurisdiction from a specialised convention to which the first State is a party as well and which contains specific rules on jurisdiction, even where the defendant, in the course of the proceedings in question, submits no pleas on the merits.