DUBAI (Reuters) - Reformist former Vice-President Mohammad Reza Aref has withdrawn from Iran's June 14 presidential election, he said in a statement carried by the ISNA news agency on Tuesday.

The sole reformist candidate still standing in the election, Aref said he had received a message from reformist former President Mohammad Khatami on Monday evening saying his remaining in the race was not "expedient".

"In consideration of Mr. Khatami's explicit opinion, and the experiences of two past presidential elections, I declare my withdrawal from the election campaign," Aref said. He urged people to turn out and vote on Friday, but did not endorse any other candidate.

Aref's withdrawal comes after calls from reformists for him to unite in a coalition with moderate cleric Hassan Rohani, who is still in the running for the presidency.

Aref's statement did not mention Rohani or a coalition, but Khatami has stated his support for such an electoral alliance.

The June 14 presidential vote will be Iran's first since 2009, when two reformist candidates said Mahmoud Ahmadinejad's re-election was fraudulent, sparking months of popular protests.

(Reporting by Yeganeh Torbati; Editing by Louise Ireland and Jon Hemming)