Circle Health is a private company which runs six hospitals and took over the management of the NHS Hinchingbrooke Health Care Trust in November 2011. Backed by some of the UK’s most powerful hedge funds, Circle’s employee-ownership model initially received much attention from policymakers and was variously described as 'social enterprise majority owned by employees' and a 'John Lewis-style mutual', a 'third-sector provider'. 
Questions raised over its financial situation and contracts saw the proposed flotation of its parent company Circle Holdings on the Alternative Investment Market (Aim) put back from June 9 until 17 June 2011  though it ultimately went ahead. Despite its public listing, almost 95 per cent of shares have remained in the hands of six investors, including the above-mentioned funds.
According to its London Stock Exchange listing, "Circle is 50.1 per cent owned by the Company and 49.9 per cent owned by the Circle Partnership which is 100 per cent beneficially owned by Circle's clinicians and employees. Circle's objective is to redefine secondary healthcare delivery in the UK. It benefits from a unique operating model which has been successfully applied and proven, whereby clinicians are empowered to achieve high levels of patient care and efficiency, through co-ownership and active participation in managing operations." 
From 'The Return of the Public' blog, 30 Nov 2010:
- A company called Circle has taken over the running of Hinchingbrooke hospital. On November 25th, the mastermind behind the Coalition’s plans for a Big Society, Phillip Blond, tweeted that - 'Circle are an employee owned mutual – great news that they have won the contract to run Hinchingbrooke – its mutualisation not privatisation'. The Daily Telegraph picked up the theme. On same day it wrote that Circle operates a ‘John Lewis-style partnership model’.
- In fact the company is majority owned by private investors, as their website makes clear: 49.9% of Circle is owned by Circle Partnership Ltd, which is owned by everyone who works in clinical services, directly or indirectly and at every level. 50.1% is owned by Circle International plc. This is the investment vehicle that blue chip City institutional investors have subscribed to for shares by providing the capital for Circle. They ensure that any refinancing is achieved without diluting partners’ 49.9% ownership. The investment needed to buy land and build hospitals, clinics and invest in infrastructure is raised by Health Properties Ltd, a separate business.
- The Coalition are pursuing privatization by stealth. I hope the John Lewis partnership and the country’s mutuals will make it clear they are not structured like Circle and do not wish to be likened to a company where employees can be outvoted by external shareholders."
In June 2011 The Bureau of Investigative Journalism found that Circle was "just one subsidiary in a complex corporate structure that spans the British Virgin Isles and Jersey".
- Its backers include Lansdowne Partners, which owns 18.9% of Circle Holdings. The investment company was founded by Tory donor Paul Ruddock. Other shareholders include Odey Asset Management with a 21.4% share; its founder, Crispin Odey, pocketed £28m in 2008 after betting correctly that Bear Stearns would collapse. He also funds the Tories. 
- Ali Parsadoust, Managing partner, Circle. Parsa ranked 97 in the Health Service Journal's list of top health industry influencers. He has an engineering doctorate and a successful banking career behind him including as a Goldman Sachs vice-president. He spoke alongside health secretary Andrew Lansley at a big society debate in 2010.
- Christina Lineen, head of communications. Lineen is a former aide to health secretary Andrew Lansley. She worked for him for two years, joining Circle in July 2010. She replaced Nick Seddon, who left earlier in the year after about 18 months to join the think tank Reform as deputy director.
- Massoud Fouladi, Chief Medical Officer and co-founder of Circle.
- Garri Jones - Head of Financing - former Executive Director of the Equities Division of Goldman Sachs 
- Jacqueline Droogan, Head of Commissioning. Joined Circle from the Birmingham New Hospitals Project (BNHP), where she spent 6 years, most recently as Deputy Project Director. Was responsible for managing various programmes, including a £560m Private Finance Initiative for acute and mental health facilities, one of the UK's largest. 
- Tamasin Cave, The privatising cabal at the heart of our NHS Spinwatch, 1 April 2015.
- Melanie Newman and Nick Mathiason, Questions grow over private health firm Circle Health ahead of flotation, Bureau of Investigative Journalism, 5 June 2011.
- website: http://www.circleholdingsplc.com
- Business leader, Circle Health – the 'social enterprise' run by the world's hardest hedge fund managers, The Observer, Sunday 13 November 2011
- Melanie Newman, Circle Holdings delays Stock flotation, 7 June 2011, The Bureau of Investigative Journalism, accessed 8 June 2011
- Melanie Newman, Circle plans further NHS hospital takeovers, 17 June 2011, The Bureau of Investigative Journalism, accessed 23 June 2011
- London Stock Exchange, Circle Holdings, accessed 23 June 2011
- Dan Hind, The Return of the Public, The Big Society: How it Works, 30 Nov 2010
- Melanie Newman and Nick Mathiason, Questions grow over private health firm Circle Health ahead of flotation, 5 June 2011, The Bureau of Investigative Journalism, accessed 6 June 2011
- Health Service Journal, HSJ100 2010, 17 November, 2010 (subscription required)
- Public Affairs News, Private healthcare firm Circle recruits ex-Lansley aide to head comms, July 2010
- [Management team], accessed 6 June 2011
- Jacqueline Droogan, accessed 5 June 2011