Allen & Overy (A&O) and Linklaters & Alliance are set to fight it out for the position of primary UK corporate adviser to German multi-utility RWE following its acquisition of the UK's largest electricity supplier, Innogy.

Innogy agreed to a £3.1bn cash offer from RWE last month in a deal that will see the German company taking on an additional £2.1bn of debt and £300m in contract liabilities.

The deal saw A&O secure its most significant corporate instruction yet from RWE after Linklaters – which is considered to be the client's primary UK corporate adviser – was immediately conflicted due to its long-standing ties to Innogy.

Linklaters advised RWE on its last major UK corporate transaction when it acquired Thames Water in 2000, although the client has also instructed A&O in the past.

Both firms are now hoping to cement ties within the newly-merged company, with Innogy's executive team expected to remain intact as part of the deal.

Corporate partner Alan Paul led the A&O team advising RWE with Linklaters corporate partner Charlie Jacobs leading the team advising Innogy.

Hengeler Mueller and Cravath Swaine & Moore advised RWE on German and US law respectively, while Innogy used Shearman & Sterling for its US advice.

Jacobs said: "We have strong relationships with RWE and Innogy and hope to continue working closely with both of them."