Irish Nationwide has been fined €50,000 for breaching regulations in relation to an email sent last week.
The Financial Regulator found the Building Society failed to act professionally and have regard to the integrity of the market.
Late last week it emerged the son of Irish Nationwide’s Chief Executive had sent an email touting for business in Britain on the back of the government's move to guarantee all deposits in six Irish financial institutions, including Irish Nationwide.
The Financial Regulator said it had reasonable cause to suspect the Building Society committed a breach of a regulatory requirement, and launched an investigation.
Irish Nationwide has also been reprimanded by the Regulator, and the matter is now considered closed.