 To ensure independence and to provide protection against involuntary take-overs by competitors, SMN, KRL and KPM formed a cartel under the name "NV Nederlandsche Scheepvaart Unie" in 1908, which also meant that the individual shipping companies were restricted to their agreed trading areas.Highlights of the pre-war developments were the introduction of passenger mail services sailing alternating from Amsterdam and Rotterdam via Suez and the Red Sea to Batavia, in addition to the regular freight services.The inter-island service with connections to Hong Kong was provided by the KPM and JCJL with passenger-mail vessels.