Maurel & Prom said on Monday that its possible offer was priced at 17 pence per share for Amerisur, whose shares closed at 16.52 pence on Friday. Maurel said Amerisur could help the French group boost its range of assets in Latin America.

The offer would comprise 12.5 pence in cash and new shares in Maurel worth 4.5 pence each, valuing Amerisur at around 210 million pounds in terms of stock market capitalisation.

However, Amerisur Resources said the possible offer undervalued the company, and added it had been in talks with other possible bidders as well.

"Following the approach from Maurel & Prom concerning its possible offer and the receipt of other interest in the company, the board concluded that the Maurel & Prom possible offer materially undervalued the company and was not at a level, nor in a form, that merited further consideration," Amerisur said.

Amerisur's shares rose 7% in London, while Maurel & Prom shares gained 3.4%.

Maurel & Prom's interest in Amerisur highlights a wave of takeover activity in the energy sector as companies look to increase their size to boost cash flow and quell investor criticism over a lack of returns.

Earlier this year, Occidental Petroleum made a proposed $38 billion acquisition of Anadarko Petroleum, while Callon Petroleum announced a takeover of Carrizo Oil & Gas Inc in July.

The Paris-based company said Amerisur's main assets were in Colombia and Paraguay, and they would fit well with its own assets in Colombia.

"M&P sees considerable benefit to shareholders from a combination and believes that the enlarged group would offer significant value upside for both Amerisur's and M&P's shareholders," the French company said in a statement.

"The combination would result in a balanced portfolio of producing assets, with a wide range of high-impact exploration and development opportunities across Latin America and Africa," added Maurel & Prom.

Maurel & Prom said that if it did succeed in acquiring Amerisur, it would seek a stock market listing later on the London Stock Exchange.

(Reporting by Sudip Kar-Gupta, Editing by Sherry Jacob-Phillips and Dale Hudson)

By Sudip Kar-Gupta