Iran's long-serving parliament speaker will retain his post despite gains by reformists in elections held earlier this year.

The official IRNA news agency says Ali Larijani, 59, was re-elected by 173 out of the body's 281 lawmakers. He defeated Mohammed Reza Aref, who was considered more open to expanding social and political freedoms.

IRNA says Larijani, who has been speaker for the last eight years, was voted interim speaker on Sunday. He is expected to be re-elected once the credentials of new parliament members are verified.

Larijani supports President Hassan Rouhani's foreign and economic policies, including the landmark nuclear agreement reached with world powers last year.

Moderates and reformists who support Rouhani won the most seats in elections held earlier this year, marking a shift away from hard-liners.