CAIRO (AFP) - Egypt's army chief Abdel Fattah al-Sisi, who led the ouster of Islamist president Mohamed Mursi, has been promoted to the rank of field marshal, the highest in the military, the presidency said on Monday.

"Interim president Adly Mansour issued a presidential decree promoting General Abdel Fattah al-Sisi, minister of defence, to the rank of field marshal," the presidency said.

Egypt's military rarely promotes senior officers to the rank of a field marshal.

Long-time ruler Hosni Mubarak, toppled by a popular uprising in 2011, and his predecessors, who all came from the military, were never promoted to the highest military rank.

However, Mr Hussein Tantawi, the former military chief who ruled Egypt between Mr Mubarak's ouster in February 2011 and Mr Mursi' election in June 2012, also holds the rank.

Mr Mursi replaced Mr Tantawi with General al-Sisi as army chief and defence minister in August 2012.