DUBAI (Reuters) -Ali Shamkhani, long-time ally of Iran's supreme leader, has stepped down as the country's top security official, Iranian state media said on Monday, two months after signing a China-brokered deal with Saudi Arabia to end political rift.

An Iranian insider said the change in leadership at the Supreme National Security Council was unlikely to have an impact on its policies and that Shamkhani might be considered for a "more important position" in Iran.

He did not elaborate, but with a parliamentary election due in February - when analysts believe the turn out will be low amid mounting political dissent and growing economic hardships - such moves of senior personnel are being closely watched.

A Revolutionary Guards commander, Ali Akbar Ahmadian, has replaced Shamkhani, state media said, who served as chief of the Guards Joint Staff in the 2000s and later as head of its strategic centre.

Seen as the only ethnic Arab Iranian in such a senior position in the Shi'ite-dominated Iran, Shamkhani inked a China-brokered deal with Saudi Arabia in April that ended years of political rift between the regional rivals.

Active across the political spectrum in the Islamic Republic for decades, Shamkhani was appointed the secretary of the security council in 2013 and served as defence minister under two-term reformist president Mohammad Khatami from 1997 to 2005.

Born in Iran's oil-rich Khuzestan province in 1955 to a family from a minority group of Iranian Arabs, Shamkhani joined Iran's Guards shortly after its formation in 1979. He served as deputy commander of the Guards from 1981 to 1988.

(Additional reporting by Elwely Elwelly; Editing by Hugh Lawson and Alison Williams)