Ophir Energy Plc shareholder, Petrus Advisers, on Feb. 20 called for alternatives to Medco Energi Internasional Tbk's takeover offer to be presented immediately and asked the company to put Petrus-backed directors in charge of overseeing the proposed changes.

Petrus, which owns a more than 3% stake in Ophir, said the company must present an alternative to Indonesia-based Medco's offer of 55 pence per Ophir share that guarantees at least $100 million in tax-efficient distributions to investors.

Proceeds that Ophir may get for its Mexican license and its Tanzania assets must also be added to the $100 million in returns, said Petrus, which believes that Medco's offer undervalues Ophir's assets.

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"At this point, Medco is paying less than the fair value of Ophir's South East Asian production assets meaning they are gifted substantial synergies and the upside potential from Ophir's licenses in Tanzania, Mexico and Equatorial Guinea," Petrus said.

Medco, which earns the bulk of its revenue from oil and gas operations in Indonesia, also stands to gain access to international assets in Tanzania and Mexico through the deal.

Ophir and Medco each declined to comment.

Petrus also called for Ophir to resume talks with government of Equatorial Guinea about compensation for its license to the Fortuna oil block in the Central African country, which the government did not extend despite a $700 million investment by Ophir.

Ophir last month projected a non-cash write down of $300 million in its full-year results after being denied the extension.

Petrus, Ophir's eleventh biggest shareholder, blamed the board for preferring to sell Ophir at "sub-optimal terms" rather than fight for shareholder value, while pointing out that Ophir's share price has fallen 87% since Chairman Bill Schrader joined the oil and gas company.