Edinburgh-based Capricorn Energy said on Tuesday it is “exploring a number of expressions of interest relating to alternative transactions” to the all-share merger with London-based Tullow Oil it announced on June 1.

Bloomberg has reported that more than a quarter of Capricorn’s shareholder base could vote against the deal.

The takeover by Tullow requires the support of at least 75% of Capricorn’s shareholders who cast ballots.

Under the deal announced on June 1, Capricorn shareholders would receive 3.8068 new Tullow shares for each Capricorn share held, with Capricorn shareholders to own 47% and Tullow shareholders to own 53% of the combined company.

Reuters calculated the value of that proposed deal at roughly £657 million.

In a half-year report, Capricorn Energy CEO Simon Thomson said: “Almost one year since the acquisition of the Egypt business, we continue to make good progress and have been successful in prioritising oil and liquids production growth while current commodity prices remain high.

“We were delighted to return more than US$500 million to shareholders following receipt of the India tax refund at the beginning of the year.

“The board continues to believe that the proposed merger with Tullow can deliver significant long-term value for shareholders through creating a leading, Africa-focused energy company.  

“The board is also mindful of the impact of external factors and market conditions and is, as always, assessing all options to maximise value for shareholders.

“The company is exploring a number of expressions of interest relating to alternative transactions, and is engaging with those parties expressing interest to evaluate potential outcomes.”