Vladimir Yevtushenkov was freed from house arrest on Wednesday, Interfax reported. He had been held on charges of money laundering connected to a deal to acquire a stake in oil company Bashneft. That stake has been returned to the state.
Putin told his annual end-of-year news conference that the so-called Bashneft case was not linked to any wider revision of the privatisation of state assets.
Shares in Sistema rose strongly after Putin's comments, extending gains of some 60 percent to trade up around 90 percent on the day.