Sisi, who was also defense minister, faces no serious competition in the election -- likely before June -- and is expected to win comfortably, riding on a wave of popularity for his law and order message.

But the Muslim Brotherhood movement of president Mohamed Morsi, whom Sisi toppled in July, warned there could be no stability in Egypt under the "shadow" of his leadership.

The Brotherhood and its allies have kept up their protests against the overthrow of Egypt's only freely elected president against a backdrop of mounting violence by militant groups that has killed scores of police and troops.

Sisi declared his widely anticipated candidacy in a televised address to the nation.

"Today, I stand before you for the last time in a military uniform, after deciding to end my service as defense minister and commander of the armed forces," he said, dressed in his field marshal's uniform and sitting behind a desk.

"With all modesty, I nominate myself for the presidency of Egypt."

Sisi's candidacy is likely to be welcomed by the millions of Egyptians who are weary of more than three years of turmoil since the overthrow of Hosni Mubarak.

But it is likely to further inflame Islamist protests and worry those secular activists who fear a return to rule by military men and the strong-arm tactics of the Mubarak era.

NJF/NJF