Allen & Overy (A&O) has landed the key role advising Ernst & Young (E&Y) on the £2.6bn restructuring of struggling transport group Metronet.

The role is a major boost for the magic circle law firm, which is advising E&Y as administrator on the largest formal insolvency procedure ever seen in the UK. Insolvency head Mark Sterling and restructuring partner Katrina Buckley are leading the team for A&O.

The announcement today (18 July) that Metronet is going into administration marks the UK's first-ever public-private partnership (PPP) project to become insolvent.

CMS Cameron McKenna is acting for Metronet. The City firm has a longstanding relationship with the group, having advised on its initial £14.8bn PPP investment in the Tube network in 2003. Projects partner Andrew Ivison is leading the team for Camerons.

Herbert Smith head of projects Nicholas Tott and corporate recovery chief Kevin Pullen are advising Transport for London (TfL), which applied on behalf of the Mayor of London to have Metronet put into administration.

The move follows an extraordinary review of the company, which had requested £551m in emergency funding to operating but was granted just £121m. Metronet says it does not have access to funds to enable it to carry out its contractual obligations.

Clifford Chance restructuring partner Mark Hyde is advising a collection of lenders, while Ashurst is advising Deutsche Bank as the security trustee and agent through restructuring chief Nick Angel and partners Nick Avery (projects) and Richard Kendall (finance). Ashurst advised the initial lending consortium on the 2003 project.

The project has five different groups of lenders and two separate public bonds, with EIB the senior debt lender.