* This content was produced in Russia where the law restricts coverage of Russian military operations in Ukraine

MOSCOW, Nov 10 (Reuters) - Russia's SPB Exchange, which specialises in trading foreign shares, has sought international legal advice on how to transfer shares and payments to investors after a trading halt last week due to U.S. sanctions, CEO Yevgeny Serdyukhov said on Friday.

The U.S. Treasury last week targeted SPB as part of sweeping new measures that also aim to curb Russia's future energy capabilities and sanctions evasion, which forced a halt in trading and the exchange to tweak its strategy to focus on settlements in roubles.

Market players sought to sell shares when the U.S. Treasury Department's Office of Foreign Assets Control (OFAC) added SPB, Russia's second-largest bourse, to its SDN list. That addition freezes assets held in the United States and bars U.S. companies or citizens from trading with those listed, freezing them out of all dollar payments.

Serdyukhov said the exchange's foreign intermediaries had demanded SPB carry out compliance.

"We were forced to suspend trading and now only settlements on transactions concluded before the sanctions were imposed are available to us," Serdyukhov said in a video message.

The bourse now has a queue of transactions from several days, but expects progress from Monday, said Serdyukhov.

SPB is developing a process with international sanctions lawyers on how the shares will be delivered, the money transferred and in what currency. Details will be published in due course, said Serdyukhov.

The exchange last week said the sanctions would not affect clients' asset holdings, but Russia's central bank has warned that the SPB faces a serious challenge in finding long-term viability should foreign asset trading be diminished.

"We have always warned that owning foreign securities carries certain risks," Bank of Russia Governor Elvira Nabiullina said this week.

She estimated that about 80% of the volume of foreign shares was blocked.

The central bank is also assessing the readiness of Moscow Exchange, Russia's largest bourse, to deal with potential sanctions, Nabiullina said. (Reporting by Elena Fabrichnaya in Moscow and Alexander Marrow in London; Editing by Emelia Sithole-Matarise)