ASTANA, Sept 21 (Reuters) - Gold and silver producer Polymetal International plans to sell all of its Russian assets rather than split them up, and will hire an adviser for the deal soon, chief executive Vitaly Nesis said on Thursday.

The United States in May included Polymetal's Russian business and Polyus - the largest gold producers in Russia - on its latest list of sanctions targets, aiming to punish Moscow for its actions in Ukraine.

Polymetal International completed re-domiciling to Kazakhstan from Jersey last month, getting a listing on the Central Asian nation's Astana International Exchange (AIX) and saying it would sell the Russian business within nine months.

"I think that selling the Russian business part by part would definitely destroy much of shareholder value," Nesis said, when asked about the plans in Astana. "So we are not considering the option of selling parts of the business."

Nesis said the new Russian rule requiring investors from "unfriendly" jurisdictions to sell assets at half their market price would not apply to Polymetal thanks to its redomiciliation to Kazakhstan.

He also said Polymetal would not sell the business to an entity on the U.S. sanctions list, which rules out Polyus as a buyer. Nesis declined to name any potential buyers and said talks were yet to start.

"This will not be a fire sale; we must sell this asset for a lot of money," he said. (Reporting by Tamara Vaal Writing by Olzhas Auyezov. Editing by Gerry Doyle)