Last month, the Financial Times reported that Oleg Deripaska, Viktor Vekselberg and Andrey Kostin had been told to stay away from the high-profile forum, due to take place in January, due to caution over dealing with businessmen under sanctions from Washington.

In response, Russia threatened to boycott the forum completely. "No one will go there," Prime Minister Dmitry Medvedev was cited by Interfax news agency as saying, after the report.

Davos forum organisers have now changed their minds, RIA cited its government source as saying.

"Since the Davos forum organisers have changed their decision and lifted the restrictions they imposed earlier on Russian businessmen, an official government delegation will travel to Davos and take part in the forum," RIA cited the source as saying.

"The level of the delegation and its composition will be decided later," the source said.

Russian billionaire Deripaska was placed under U.S. sanctions in April along with companies in which he is a large shareholder, including Rusal, the world's biggest aluminium producer outside China.

Vekselberg and his Renova Group, and Kostin, head of Russian state bank VTB, were also targeted by U.S. sanctions at the time.

(Reporting by Polina Ivanova; Editing by Louise Heavens)