Royal Bank of Scotland's Chief Executive Stephen Hester said on Tuesday it will take another 18 months to improve the bank's capital position enough to keep regulators happy.

"Our capital ratios are transformed but we have another 18 months or so to get them in the final shape that we and our regulators want," Hester told shareholders at the bank's annual meeting in Edinburgh, Scotland.

Chairman Philip Hampton said that the bank should "substantially complete" its restructuring in 2014, enabling it to return to the private sector "as soon as we can".

(Reporting by Steve Slater and Matt Scuffham, Editing by Kirstin Ridley)