Ulster Bank made a first half operating profit of £55m (STG), according to an unexpected trading update released today.

Parent group Royal Bank of Scotland (RBS) says Ulster Bank's impairment charge is significantly down for the first half of the year, from half a billion pounds to £57m.

The group did not comment on a possible sell-off of Ulster Bank.

RBS shares opened nearly 10% up after the news.

The group says they will release a full statement, including commentary, next week.

Our Business Editor Ian Guider explains:

RBS in the UK is actively managing a slate of legacy issues concerning conduct and litigation issues in the UK that will hit profits, and could impact any decision regarding the possible sell-off of Ulster Bank.