A London-based investment manager and one of the top ten shareholders in John Wood Group has written to the Aberdeen-headquartered firm calling on the chairman to explore a US listing or a sale of the company.
The engineering services company was at the heart of a £1.7bn bid- worth 240p a share - almost a year ago from Apollo Global Management.
But Wood's share price has slumped 40% since then to around 140p a share, prompting Sparta Capital Management to call for a strategic review of the firm.
Wood Group never rejected Apollo's offer, which was the fifth one tabled by the American private equity firm. Apollo abandoned their interest around a month after submitting the bid.
In a letter to Wood chairman Roy Franklin, Sparta said: "If the UK public markets are unwilling or unable to engage in Wood's story, we believe you should undertake a strategic review and actively seek alternative solutions."
Sparta also noted the "recent successful attempts by corporates to move their primary listing away from markets which they have determined do not recognise the true worth of their businesses."
The investment manager praised Wood for it's "many operational achievements" since a new corporate strategy was implemented 18 months ago.
But the letter added: "If you conclude that shareholder value will be maximised through a sale of the company, we encourage you to engage with any suitable bidders who may emerge during this process."
Sparta has declined to comment on the letter, which was seen by Sky News, and Wood has yet to comment.
Shares on Monday at Wood Group closed at 140.4p.