BRUSSELS, May 17 (Reuters) - Organic and conventional farmers will face extra costs keeping their produce "GM-free" once genetically modified crops become more common in Europe, the European Commission said on Friday.</p><p><a href="http://www.agriculture.com/worldwide/IDS/2002-05-17T144104Z_01_L1779050_RTRIDST_0_FOOD-EU-GENES.html">@gWorldwide - EU says farmers face extra costs to stay GM-free</a>