Royal Dutch Shell and its two Japanese partners are to be made to share the burden of the huge cost overruns of Sakhalin-2, it emerged on Thursday, in news that cast a less favourable light on their deal to cede control of the project to Gazprom.

Just days after confirming that Russia would pay the companies $7.45bn to establish its controlling stake in the project, the government said it would require the three foreign owners to meet $3.6bn of the additional costs of Sakhalin-2 themselves.