Election officials: Ahmadinejad leading as final result nears

With 78 percent of ballot boxes counted, Ahmedinejad had 64.9 percent of the vote while his chief rival Mir Hossein Moussavi had 32 percent, election officials said.

Analysts expected Moussavi, widely regarded as a reformist, to do well as his campaign caught fire in recent days, triggering massive street rallies in Tehran.

An "unprecedented" voter turnout at the polls Friday was also expected to boost Moussavi's chances of winning the presidency.

Iran's Interior Minister Seyed Sadeq Mahsouli said 70 percent of 46 million eligible voters had gone to the polls Friday, according to Fars, another semi-official news agency.