A haul truck being loaded with iron ore at a Rio Tinto mine in the Pilbara region of Western Australia is seen in this undated handout photograph obtained May 3, 2010. Australian mining shares tumbled on Monday after the government slapped the industry with a new 40 percent profits tax, prompting global miners to warn that billions of dollars in new projects were at risk. REUTERS/RIO TINTO/Handout (AUSTRALIA — Tags: ENERGY BUSINESS) FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS