Russia's authorities have told Schlumberger to forget about its plan to acquire a controlling stake in the country’s leading drilling provider Eurasia Drilling, after nine months of talks.

Speaking in Moscow at the end of last week, Igor Artemyev, the head of Russia's federal anti-monopoly service, said the governmental commission for foreign investments decided Russian shareholders should retain a minimum 50% stake plus one share in Eurasia in order to keep operational control.