Under the terms of the letter, RNS will be used by the ISE to distribute all announcements from the Irish Stock Exchange.
Andrew McStravick, the London Stock Exchange's Director of Operations, welcomed the ISE's decision to appoint RNS as its sole regulatory news provider: "When the FSA decided to commercialise regulatory news distribution, we set ourselves the clear goal of ensuring that RNS would be the leading provider," he said.
"The Irish Stock Exchange's decision to appoint RNS is an important step towards this and, based on the positive customer feedback we are receiving about RNS, we are confident of achieving our goal."
James Ferguson, the Irish Stock Exchange's Operations Manager, said: "RNS has many years of experience of distributing regulatory information and we know that they will provide a secure, reliable and comprehensive service."
