The five companies are CGN Power, China National Nuclear Power, China Shipbuilding Industry, Inspur International and Sinochem International.

"FTSE Russell will continue to monitor for any communications from OFAC (the U.S. Office of Foreign Assets Control) throughout today and will provide an update on index treatment no later than 1700 GMT (1200 EST) 26 January 2021," FTSE Russell said in a statement.

(Reporting by Marc Jones; Editing by Tom Arnold)