The Muslim Brotherhood will not nominate one of its members for the post of prime minister, the Islamist group's secretary general, Mahmoud Hussein, said in a press statement on Sunday.
Hussein added that the issue was not even discussed at the last meeting of the group's governing body, the guidance bureau.
The appointment of new a prime minister is for the president to decide, nobody else, Hussein said.
There had been rumours that the Brotherhood's deputy Supreme Guide, Khairat El-Shater, might be offered the prime minister job.
President Mohamed Morsi is a long term member of the Muslim Brotherhood, Egypt's largest and most influential Islamist group.
Morsi's spokesperson said Saturday that the new government would be announced shortly, and denied reports that the president himself would head a new cabinet.