Ratings agency Fitch has today upgraded Ulster Bank Ireland DAC's credit rating from BBB to A- .

This follows an upgrade of the credit rating of the bank's UK parent - Royal Bank of Scotland - last week from BBB+ to A with a stable outlook.  

Fitch said Ulster Bank's upgrade reflected the agency's expectation of an "extremely high probability" of support from Royal Bank of Scotland if required. 

"We believe that any support required by UBI would be manageable for RBSG, given the subsidiary's size compared with the group's financial profile," Fitch said.

It said RBS has identified Ireland as a strategically important market.

Fitch also said it believed that if the group does not provide support if needed, it would cause high reputational risk with potential for a significant negative impact on other parts of the group.