Shares in BlueScope Steel are down more than 17% in early trade, after the company reported its full-year results this morning. The company reported an annual net profit after tax of $US715.9 million, slightly above market expectations and up 112% from the prior year. CEO Paul O'Malley also announced that he would be stepping down after 10 years in the role, to be replaced by Mark Vasella effective from January 1, 2018. The fall in the share price may be stemming from an announcement by the company this morning that it was the subject of a regulatory investigation. Here's the text from BlueScope's contingent liabilities note in its 2017 financial statements: "Over the last financial year, the Australian Competition and Consumer Commission (ACCC) has been investigating potential cartel conduct by BlueScope relating to the supply of steel products in Australia, that involved a small number of BlueScope employees in the period from late 2013 to mid-2014.