UPDATE 1-Uncertainty clouds Itaú's view on corporate defaults, CEO says

SAO PAULO, Aug 20 (Reuters) - Itaú Unibanco Holding SA , Brazil's No. 1 bank by market value, is having a difficult time predicting trends in corporate loan delinquencies amid an uncertain outlook for some industries and policies to shore up the economy, Chief Executive Officer Roberto Setubal said on Thursday.