John Menzies has labelled a £469 million takeover approach as “opportunistic” as it reiterated its rejection of the potential deal.

The Edinburgh-based firm – which provides fuelling, ground handling, lounge and maintenance services – saw its shares surge more than a third last week after it received a 510p-a-share unsolicited bid proposal from National Aviation Services (NAS).

The bidder is an aviation services provider in emerging markets, which has its headquarters in Kuwait and is part of the wider Agility Public Warehousing Co.

However, John Menzies swiftly turned down the proposal, which came months after an earlier 460p per share move by NAS was also rebuffed.

On Monday, the Kuwait-based suitor suggested it would not raise its offer soon, describing its proposed deal as “full and fair” for the UK business.

Shares in John Menzies dropped back on Monday as a result.

NAS chief executive Hassan El-Houry said: “We made a compelling offer that represents a 76% premium to the share price less than two weeks ago.

“As operators ourselves, we also see a sector facing a number of challenges and a company that lacks the balance sheet to thrive.”

He also blasted Menzies for failing to engage properly with NAS and said he intended to speak to shareholders directly.

In a new update on Tuesday, Menzies said it has engaged with its shareholders following the approach.

“As previously announced, the Board of Menzies has unanimously rejected the NAS Proposal, having concluded that it is opportunistic, conditional and that the terms fundamentally undervalue Menzies and its future prospects,” the company added.

The company said it believes its current strategy will “create significant value for shareholders in the near and medium term” as it sought to reassure shareholders.

Shares in Menzies were 4.3% higher at 485p per share in early trading.