The state-controlled bank said in December that it had applied to the courts to move 6 billion pounds of assets and 7 billion pounds of liabilities to its Dutch subsidiary NatWest Markets N.V.

The proposed plan impacts about 30 percent of NatWest Markets' customers who are located in the European Economic Area.

RBS said on Friday that certain existing transactions for some European Economic Area customers will transfer from NatWest Markets Plc to the Dutch hub on a date between March 23 March and Dec. 31.

"The flexibility of Phase 2 is designed to take advantage of any transitional period or other possible outcomes of the Brexit negotiations," it said.

(Reporting by Noor Zainab Hussain in Bengaluru, editing by Huw Jones)