CAIRO, Jan 6 (Reuters) - Egypt's foreign currency reserves fell to $15.33 billion at the end of December from $15.88 billion the previous month, the central bank said on Tuesday.

Foreign reserves fell sharply after the 2011 uprising that ousted President Hosni Mubarak but had risen again on the back of billions of dollars of Gulf Arab aid that has flooded into Egypt since the army overthrew elected Islamist President Mohamed Mursi last year.

In November, Egypt repaid to Qatar a $2.5 billion central bank deposit received under Mursi, which some traders had warned could have an impact on reserve levels.

Reserves stood at about $36 billion before the 2011 revolt. (Reporting by Lin Noueihed; Editing by Andrew Heavens)