The European Commission is investigating a tax measure allowing troubled German companies, whose shareholdings undergo major changes, to carry forward fiscal losses. The Sanierungsklausel policy, introduced by the German Government in 2009 but applying retroactively to 1 January 2008, enables ailing companies with the potential to be resuscitated to reduce their corporate tax liabilities by setting off previous years' losses against any taxable income. The German Government denies that the system involves any form of State aid and the Commission accepts that it is matter for national administrations to decide when companies can carry forward losses from taxable income. However, if the system is selective in nature and is discriminatory, it could constitute State aid. The Commission therefore opened an in-depth investigation on 24 February 2010, to ascertain whether the system contains elements of aid and if so, whether that aid is consistent with the EU Guidelines on Rescue and Restructuring aid.