The Russian mergers and acquisitions market is likely to close until after the presidential elections, although bankers were at pains to play down the long-term significance of Khodorkovsky's arrest. Constantine Gonticas, head of Central Europe, Middle Eastern and Russian investment banking at Merrill Lynch, said: "The strategic rationale for investing in Russia has not been rendered invalid by recent events."

Since the arrest of Khodorkovsky, Danone, the French food group, has postponed its €900m ($1.1bn) acquisition of Wimm-Bill-Dann, the Russian dairy products and fruit juice group, while last week Russian authorities seized a controlling stake in Yukos. Danone is waiting to gauge the impact on Wimm-Bill-Dann's share price, although if it falls too far the deal could be scuppered.