Activist shareholder James Dunphy has urged investors in AWE to ignore the board's recommendation to accept Mitsui's 95¢ a share takeover offer, telling them the stock is worth $1.10 a share and throwing a potential hiccup in the way of the $602 million cash takeover.

The unanimous recommendation from the Kenneth Williams-led board is "demonstrably not in your best interests," Mr Dunphy, a long-term critic of AWE's board, wrote in a letter to shareholders published on his website.