Scandal-hit outsourcing group Serco has named former Centrica boss Sir Roy Gardner as its new chairman as the company seeks to turn around its fortunes.

Sir Roy will take over as non-executive chairman on July 1, ending a six-month search to replace Alastair Lyons after he announced plans to step down in November, saying he took ultimate responsibility for the group's 'strategic and operational missteps'.

Serco was thrown into crisis in 2013 when it had to repay the Government £68.5 million for overcharging on criminal tagging contracts as well as £2 million from past profits for a prisoner-escort deal.

A series of profit warnings have since followed and the group has seen its share price slashed in half over the past year.

The appointment of corporate veteran Sir Roy will provide a boost to turnaround efforts by recently hired chief executive Rupert Soames.

Since taking over last May, Mr Soames has been seeking to beef up the company's management and board as part of a drastic overhaul to improve the group's relationship with the Government and make the business smaller and more focused.

Mr Soames said: 'I am greatly looking forward to working with Sir Roy, whose broad experience in areas relevant to our business will be extremely valuable.'

He added: 'I would also like to thank Alastair Lyons for all his hard work and support, particularly over the last 12 months, as we have developed a new direction for the company and put it on a solid financial footing.'

Sir Roy will be paid £250,000 a year in the post, plus expenses and allowances.

He will join the company on June 1 initially as a non-executive director - on a pro rata £50,000 salary - to allow a handover period before becoming chairman a month later.

Sir Roy said: 'Serco is a remarkable company, supporting governments around the world in the delivery of essential public services, and I look forward to working with the management team as they implement Serco's new strategy.'

Sir Roy has a wealth of experience in the corporate sector having acted as chief executive of British Gas parent Centrica between 1997 and 2006 and then chairman of catering giant Compass from 2006 to 2014.

He also previously served as chairman of Manchester United and later Plymouth Argyle Football Club.

He was knighted in 2002 for services to the gas and electricity industries.

Roger Johnston, analyst at Edison Investment Research, said: 'Serco's appointment of Sir Roy Gardner as chairman brings another heavyweight City figure to the board with significant experience across service businesses and interactions with government.'

Serco plans to re-focus as a provider of services to governments in areas such as justice and immigration, defence and transport, while looking to sell the majority of its business outsourcing operations.

The plan is being financed by a £555 million equity fundraising, approved by shareholders last month, on top of £165 million raised in a share placing last summer.

Hampshire-headquartered Serco employs 100,000 people worldwide and provides services as diverse as hospital services, the running of prisons and support for the armed forces.