(ShareCast News) - Sports Direct International said the outcome of the European Union referendum and ensuing market volatility - namely sterling weakness - will impact purchases for full-year 2017 for which the company is currently not hedged.The group pointed to a lack of transparency as to the sterling/dollar exchange rates in the short to medium term."The company continues to assess the impact of the referendum and will update the market further on announcement of the preliminary results on 7 July 2016."Earlier on Friday, British Airways and Iberia parent International Consolidated Airlines Group warned that Britain's decision to leave the EU would hit profits."Following the outcome of the referendum, and given current market volatility, while IAG continues to expect a significant increase in operating profit this year, it no longer expects to generate an absolute operating profit increase similar to 2015."At 1400 BST, Sports Direct shares were down 16% to 326p.