Pubs billionaire Bruce Mathieson is poised to lose tens of millions of dollars after his 21.5 per cent-owned Western Desert Resources became the highest-profile victim of the iron ore price slump so far, calling in administrators. The collapse of the iron ore junior, which mines the Roper Bar venture in the Northern Territory, came after Macquarie Bank lost patience with ongoing negotiations on restructuring payments on about $80 million of debt and further short-term funding needs.