Goldman Sachs is shoring up the top management of its Moscow office after a series of defections with the hiring of Russia's top regulator, one of the most influential people in the country's financial markets.

Oleg Vyugin, head of the Federal Financial Markets Service, Russian equivalent of the UK's Financial Services Authority, resigned last week and is set to join the US bank, according to Moscow market sources. Sources close to the Russian market regulator said he was Goldman-bound.