a collective agreement whose scope covers an entire industry or part of an industry,or a range of similar enterprises relating to the product,nature of productions process or raw material ..., (a) an agreement concluded at Community level between a group of national manufacturers' organisations on the one hand and a group of national sellers' organisations on the other, prior to the conclusion of any contract; (b) an agreement concluded by manufacturers or a manufacturers' organisation recognised by the Member State in question on the one hand and a sellers' association recognised by the Member State in question on the other, prior to the conclusion of any contract; (c) the provisions of the law on companies or firms and of the law on co-operatives, in so far as they govern the delivery of sugar beet by the share holders or the members of a company, firm or co-operative manufacturing sugar; (d) in the absence of any such agreement as is referred to in (a) or (b) the arrangements existing before the conclusion of any contract between a manufacturer and sellers, provided the sellers who accept the arrangement supply at least 60 % of the total beet bought by the manufacturer for the manufacture of sugar in one or more factories.