The German investment firm has purchased the stakes previously owned by the Frischmann family and part of the Prabhu family.

Pell Frischmann senior management team members, Tushar Prabhu and Richard Barrett, will become Co-CEOs.

Dr Wilem Frischmann, who has been with Pell Frischmann since 1958, will be stepping down from his role as Chairman to take on an advisory role to the incoming chairman.

The managing director of RAG-Stiftung Investment Company, Jürgen Wild, will join the Pell Frischmann board as chairman.

Wild said: “Our strategy is to invest in market leading firms with an international reach and a strong existing management team that delivers steady returns and growth.

“Pell Frischmann fits our criteria perfectly. A highly respected engineering consultancy that has an enviable reputation of combining cutting edge technical expertise with superior customer service.”

“I am committed to support the team growing the business both in the UK and abroad.”

Dr Frischmann added: “Throughout my career I am honoured to have worked with some of the best engineering minds on some of the world’s most exciting engineering projects.

“Pell Frischmann has grown to become one of the most respected consultant engineers in the business, and I am delighted that we have found an investment partner to help continue this legacy and provide an ideal platform for further growth”.