Herbert Smith Freehills, Linklaters, Norton Rose Fulbright and Ashurst have all landed roles on the Thames Tideway Tunnel's investment deal with the Bazalgette Consortium.

The deal will see the consortium of investors – including Allianz Capital Partners, Amber Infrastructure, Dalmore Capital and DIF – invest funds into the £4.2bn construction of the super-sewer under London.

Linklaters is advising Thames Water, the initial developer of the project, with a team led by energy and infrastructure partner Charlotte Morgan.

The utility company also took some advice from Sharpe Pritchard on the deal.

Herbert Smith is advising the consortium of investors. Its team on the deal is being led by its head of infrastructure Patrick Mitchell and includes finance partner David Wyles, regulatory partner Tim Briggs, construction partner Jillian Chung, real estate partner Julian Pollock, planning partner Matthew White, finance partner Jake Jackaman and partner Gavin Williams who is advising on equity issues.

Ashurst is advising the Department for Environment, Food and Rural Affairs with a team led by infrastructure partner Philip Vernon and finance partner Derwin Jenkinson.

Water industry regulator Ofwat has turned to Norton Rose Fulbright for advice.

Mitchell said: "In addition to being a hugely significant and necessary project for London, the project structure has great potential to be utilised in the provision of other infrastructure."

Thames Tideway Tunnel is also in the process of procuring building contractors to build the tunnel's three separate sections. The company is taking advice from Sharpe Pritchard on this process.

Herbert Smith is currently involved in several other major infrastructure projects including advising EDF subsidiary NNB GenCo on its new build nuclear power plant at Hinkley Point in Somerset and High Speed 2 on the procurement of the infrastructure and rolling stock for the railway from London to Birmingham, Manchester and Leeds.