Three months ago, President Abdel Fattah el-Sisi of Egypt had three close advisers: his army chief, his spy boss and his chief of staff. Just one still has a job.

On Thursday, he fired the spy chief, Khaled Fawzy, and replaced him with his chief of staff. In October, he fired the chief of defense.

In a curt statement, Mr. Sisi’s office did not offer a reason for the dismissal of Mr. Fawzy, who had led the General Intelligence Service since December 2014 and was credited with spearheading the agency’s revival after its failure to anticipate the Arab Spring in 2011.

But there were signs the decision was made quickly, mostly notably in the choice of Mr. Sisi’s longtime aide and chief of staff, Abbas Kemal, to fill the position temporarily until another successor is found.