MOSCOW, Dec. 18 - If Ukraine joins the Customs Union, export duties for energy may be cancelled, while overall Ukraine's profit from such an action may be up to $9 billion, Russian presidential advisor Sergei Glazyev said.

"There are no duties, either export or import ones, in the Customs Union. That is why the first thing Ukraine will get if it joins the Customs Union is the cancellation of export duties for oil and gas," Glazyev told a bridging in Moscow.

"Overall improvement of trade conditions for Ukraine if it joins the Customs Union will be $9 billion," he said.