Complex sentence: The registration of companies in Northern Ireland was the responsibility of Department of Enterprise, Trade and Investment until 1 October 2009, when responsibility transfered to Companies House, under the Department for Business Enterprise and Regulatory Reform (BERR).
Split into simpler sentences: The registration of companies in Northern Ireland has been the responsibility of Department of Enterprise, Trade and Investment. From 1 October 2009 responsibility transfers to Companies House, under the Department for Business Enterprise and Regulatory Reform (BERR).