The offer was set to expire Monday.
Bonterra has repeatedly recommended shareholders reject the bid. Obsidian has offered two of its shares for each Bonterra share.
In December, Obsidian reduced the minimum number of tendered shares needed to complete the transaction to 50 per cent from two-thirds.
Obsidian has said a combined Obsidian-Bonterra could save $50-million in the first year and a total of $100--million in the first three years, however Bonterra has said those savings are “uncertain.”
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