Spain's national carrier, Iberia, has replaced its auditor Deloitte with Ernst & Young.

E&Y was already auditor of International Consolidated Airlines (IAG) and British Airways however the Iberia audit had previously been retained by Deloitte after the merger with British Airways.

Hywel Ball, head of assurance, UK and Ireland at E&Y said that Iberia is an important brand which the firm is incredibly proud to include among its airline client base.

'This latest win further enhances our leading global airline credentials, which was a key differentiator in the eyes of IAG. Our Madrid and London audit teams have demonstrated the importance of exceptional client service across borders - operating with one voice across a number of complex situations, and providing challenge and insight,' said Ball.

The latest audit win follows E&Y's appointment earlier this month as auditor to Land Securities Group - the largest listed commercial property company in the UK. In the last 12 months, E&Y has also won the audit for FTSE 100 BG Group, as well as Dyson and the Audit Commission.

Energy giant Cairn dropped E&Y in March and replaced it with PwC, while HSBC embarked on a review of its current auditor HSBC in the same month.

Dutch-listed insurance group Aegon announced in February plans to change audit firm from E&Y to PwC.

The increased tendering activity among large corporations follow the Financial Reporting Council's (FRC) recommendations that companies tender their audits every 10 years or explain why they would not.

The 'comply or explain' approach is contained within the UK Corporate Governance Code, revised and published by the FRC, as part of wider moves to improve the tendering of audit services so as to ensure wider competition among audit firms since the Big Four currently dominate FTSE 100 and FTSE 350 audits.