34 The Court has also ruled that the fact that certain provisions of the Treaty are formally addressed to the Member States does not prevent rights from being conferred at the same time on any individual who has an interest in compliance with the obligations thus laid down (see Case 43/75 Defrenne v Sabena [1976] ECR 455, paragraph 31).

The Court accordingly held, in relation to a provision of the Treaty which was mandatory in nature, that the prohibition of discrimination applied equally to all agreements intended to regulate paid labour collectively, as well as to contracts between individuals (see Defrenne, paragraph 39).

37 The next matter to be considered is whether a requirement imposed by an employer, such as the Cassa di Risparmio, which makes admission to a recruitment competition conditional on possession of one particular diploma, such as the Certificate, constitutes discrimination contrary to Article 48 of the Treaty.

42 A requirement, such as the one at issue in the main proceedings, making the right to take part in a recruitment competition conditional upon possession of a language diploma that may be obtained in only one province of a Member State and not allowing any other equivalent evidence could be justified only if it were based on objective factors unrelated to the nationality of the persons concerned and if it were in proportion to the aim legitimately pursued.

46 The reply to be given to the question submitted must therefore be that Article 48 of the Treaty precludes an employer from requiring persons applying to take part in a recruitment competition to provide evidence of their linguistic knowledge exclusively by means of one particular diploma issued only in one particular province of a Member State.