of Metronet Rail became an integral part of London Underground. Some of the improvements promised by Metronet were delivered (such as new 2009 Stock and S Stock trains), however other improvements were cancelled or delayed. In 2008, the Department for Transport refuted claims that the PPP was to blame for the collapse of Metronet, and that it was "predominantly a corporate failure", with "structural weaknesses [that] led to its own downfall." In 2010 the House of Commons' Public Accounts Committee reprimanded the Department for Transport for its failure to heed National Audit Office warnings about the company's management. According to the report from the Public Accounts Committee, around £170million to £410m of taxpayer money was lost due to the failure of Metronet. The companies involved in the consortium collectively lost around £350million in the collapse. In May 2010, it was announced that TfL would buy out the Tube Lines consortium, formally ending the PPP. By the beginning of 2011, with the formal liquidation process having been completed, the Metronet brand and group of companies had ceased to exist. See also History of the London Underground References External links CityMayors article Bloomberg.com London Underground infrastructure Public–private partnership projects in the United Kingdom