CAIRO, July 16 (Reuters) - The head of Egypt's armed forces was sworn in on Tuesday as interim first deputy prime minister, as well as keeping his posts as minister of defence and military production.

The new interim government has been backed by General Abdel-Fattah al-Sisi's army that overthrew elected Islamist President Mohamed Mursi on July 3. According to analysts, the new post is likely to further increase the military's influence over political decisions.

Liberal politician Mounir Fakhry Abdel Nour, a Christian, was sworn in as interim trade and industry minister.

(Reporting by Cairo bureau; writing by Yasmine Saleh; Editing by Michael Roddy)