CAIRO, Nov 28 (Reuters) - Egypt has paid back $2.5 billion that Qatar deposited with it to help prop up the Egyptian central bank's hard currency reserves, a central bank official said Friday night.

The payment brings the amount Egypt has returned to Qatar to $6 billion, leaving $500 million outstanding, which the official said would be paid back in the second half of 2015.

Qatar helped support the Egyptian economy in the aftermath of the 2011 uprising that overthrew Hosni Mubarak, but relations have soured since the overthrow of President Mohamed Mursi of the Muslim Brotherhood last year.

Other Gulf countries have filled the void, with Saudi Arabia, the United Arab Emirates andKuwait providing $10.6 billion in aid last fiscal year, Egypt's finance minister says.

A government source said earlier this month that Egypt had received another $1 billion grant from Kuwait.

Qatar, a small gas-exporting country which provided some $7.5 billion in aid to the Egyptian government under Mursi, asked that the central bank deposits be paid back earlier this month. (Reporting by Nadia El Gowely; Writing by Shadi Bushra; Editing by Tom Heneghan)