Harbour Energy's largest shareholder EIG distributes some of its stake

"This change reflects a distribution of EIG's shareholding in Harbour to certain of its underlying investors, rather than a sale of shares," the company said.

As a result of the change, EIG is now entitled to only one shareholder nominated director on the Harbour board.

"Notwithstanding this, the board has requested that both R Blair Thomas and Steve Farris, the two EIG-nominated directors, remain on the board in light of their extensive oil and gas sector experience and the value and contribution they provide to the board," it said.

R Blair Thomas will stay on as chairman, while Steve Farris plans not to stand for re-election at the annual general meeting next year.

EIG said in a statement: "Today, EIG has distributed shares in Harbour Energy to our fund investors. As EIG is still the largest shareholder following the distribution, we remain committed to the sector, confident in the company's current strategy and supportive of its management team."

At 1430 BST, the shares were up 3.9% at 331.40p.