Nearly four weeks after making the offer, Tap’s holding in Arc has grown only from 0.427% to 0.56%. Tap told Arc shareholders it would give them more time because it believed they faced considerable risks if they did not accept .

Tap said its offer had been formulated to take account of Arc’s producing assets and the potential of its exploration acreage interests. “Tap’s offer represented a substantial premium of 34% to Arc’s share price when it was announced.

“Tap also has substantial exploration upside which is not apparent in the Independent Expert’s valuation of Tap shares,” the company said.