Michael Wilson is trying to break the deadlock in his $5bn bid for America's CF Industries by taking a leaf from his target's book, in using the annual meeting as a vehicle to break through its takeover defences.

The Agrium chief executive said he would use CF's 2010 shareholder meeting to nominate a slate of directors to the board of the Illinois-based group.

The tactic copies a strategy CF has employed to try to seal its own $4bn hostile bid for rival Terra Industries, a nitrogen fertilizer specialist.

Terra directors confirmed on Tuesday that CF had succeeded in getting three nominees voted in to join them on the board, although the victory has yet to spark any apparent erosion of the Iowa group's takeover defences.

Poison pill

Mr Wilson said that Agrium's latest strategy followed another failed attempt on Monday to open talks with CF, more than 60% of whose investors tendered their shares last month to the Canadian group's bid.

"Unfortunately, to date CF has declined all opportunities to engage directly with Agrium or its advisors," Mr Wilson said.

CF's reliance on Delaware company law to allow it to ignore the "repeatedly strong support" from its investors for Agrium's offer was "unreasonable", he said in a letter to the CF board.

"The time is overdue for you to remove these preclusive barriers and let your stockholders decide for themselves whether to accept Agrium's offer."

Mr Wilson added that Agrium remained open to "modifications" to its bid, which offers one Agrium share and $45.00 for every CF share.

However, CF stood by its position, saying "nothing Agrium says changes the fact that its offer is far from compelling."

Agrium shares closed up 5.5% at $60.11 in New York, valuing its bid at $105.11 per CF share.

CF shares closed 5.1% higher at $90.27.