Russian energy firm EN+ Group has confirmed the resignation of its president Maxim Sokov as it attempts to placate US authorities and avoid sanctions.

The US unveiled a raft of sanctions on Russia-linked companies in April this year, in response to the country’s alignment with Syria and the poisoning of former spy Sergei Skripal and his daughter in Salisbury in March, causing the Russian stock market to crash.

Shares in EN+ dropped 40 per cent when the sanctions were announced, and it has since been trying to cut ties with its oligarch owner, Oleg Deripaska. In May, the CEO and seven directors at Rusal, an aluminium company owned by EN+, stepped down.

The plan to separate the firm from its Russian owner has been dubbed the Barker Plan, named after the group’s chairman, Lord Barker of Battle.

Lord Barker said on Monday: “Maxim Sokov made a huge contribution to the development of En+ Group and our successful IPO in particular. We wish him all the best with his new endeavours.

Looking to the future, new appointments to the En+ board are a key part of the "Barker Plan" to lift sanctions against the company. This recruitment process is well underway, and I expect to be able to confirm the proposed candidates that we will be submitting to OFAC (the US Office of Foreign Assets Control) soon.”

Mr Sokov said: “En+ is currently facing unprecedented and unforeseen challenges and I have taken the decision to step down from the company for the sake of its future prosperity in anticipation of implementation of Lord Barker's plan which I fully support. I have been on a five year journey with En+ and it includes many achievements, but ultimately culminated in our London listing in November 2017.”

Investment bank Rothschild has been hired to help the group sell the 66 per cent stake currently held by Mr Deripaska, the Financial Times reported. Mr Deripaska saw around £2bn wiped off his personal wealth following the US sanctions move.