Sociedad de Inversiones Oro Blanco S.A. (SNSE:ORO BLANCO) said in a statement on December 18, 2015 that it had decided after a consultation process to invite buyers to make an offer for its entire holding in Sociedad de Inversiones Pampa Calichera, S.A. (SNSE:CALICHERAA) which will result in the stake sale of approximately 22% in Chemical & Mining Co. of Chile Inc. (NYSE:SQM), Reuters reported.