PwC is on the verge of losing another big audit contract - gas giant BG Group has confirmed it is to put out its audit contract to tender after 12 years with its auditor but would not be drawn as to who is competing for the work.

A BG spokesperson said: 'We can confirm that BG Group has tendered for the appointment of independent external auditors. This is a review based on best practice and good governance. It is sensible and prudent to market test our arrangements and requirements to ensure best value for the Group and our shareholders.'

E&Y refused to comment while the tendering process was still underway but is understood to be among the firms that may be pitching for the audit contract.

It has also been confirmed that Phoenix IT is to change its auditor, dropping Deloitte and instead handing the contract over to PwC. In September, PwC, along with Nabarro were hired by the data hosting company to conduct a forensic investigation into a misstatement of accounts that led to its shares falling 71p in value.

Last month Schroders confirmed that it was to put its audit out to tender as well, possibly ending its 50-year relationship with PwC.

The recent spate of companies reviewing their audit contracts comes amid EU proposals to shake up the audit market and amendments to the UK Corporate Governance Code made by the Financial Reporting Council.