MOSCOW, July 31 (Reuters) – Shares in United Company Rusal , the world’s second biggest aluminium producer, fell 6.8 percent on the Hong Kong exchange, in response to continued uncertainty over the company’s future following the introduction of U.S. sanctions. “There’s big volatility there,” said Kirill Chuyko, analyst at BCS Investment Bank.

“The shares have risen pretty well recently. I would say that many of the people who earned quite a bit on the news that the U.S. Treasury may lift sanctions … I think many of these people decided to sell,” he said.

The U.S. Treasury is open to removing Russian aluminum producer Rusal from a U.S. sanctions list, Treasury Secretary Steven Mnuchin said earlier this month.