BOGOTA (Reuters) - Colombia presidential candidate Rodolfo Hernandez, an eccentric construction magnate, said on Wednesday he will respect the results of Sunday's vote whether he wins or loses to leftist rival Gustavo Petro.

       Colombians go to the polls to choose between Petro, who has vowed profound social and economic change, and Hernandez, who has vowed to tackle corruption despite a pending corruption investigation against himself, the accusations of which he denies.

       "Win or lose, I will accept the result without hesitation," the septuagenarian said via social media, reiterating his confidence in electoral officials.

       Petro has previously expressed concerns of possible fraud in the electoral process, while electoral authorities have vowed that voting will be transparent.

       Opinion polls ahead of the June 19 runoff between former guerrilla Petro, 62, and construction businessman Hernandez showed they were technically tied.

       (Reporting by Luis Jaime Acosta; Writing by Oliver Griffin and Stephen Coates)