UPDATE 1-Canpotex sees to raise potash price 8 pct for China's Sinofert

Feb 25 (Reuters) - Canpotex Ltd, owned by a trio of North American potash producers, is seeking an 8 percent, or $25 per tonne price increase in its 2015 potash supply contract with China's Sinofert Holdings Ltd, Mosaic Co Chief Executive Jim Prokopanko said on Wednesday.