CAIRO, Aug 17 (Reuters) - The average yields on Egypt's six-month and one-year treasury bills rose at an auction on Thursday, central bank data showed.

Average yields on the 182-day bill rose to 19.368 percent from 18.832 percent at the last sale on Aug 10, and yields on the 364-day bill rose to 19.308 percent from 18.705 percent, the data showed.

The combined foreign contribution in the tenors on Thursday amounted to 4.5 billion Egyptian pounds, head of public debt at the finance ministry, Sami Khallaf, told Reuters.

Demand for Egypt's domestic debt has increased since the central bank floated its pound currency in November as part of an International Monetary Fund loan agreement aimed at reviving the economy. The central bank has raised its key interest rates by 700 basis points since the pound float.

(Reporting by Arwa Gaballa and Eric Knecht; Editing by Toby Chopra) ((arwa.gaballa@thomsonreuters.com; +20 2 2578 3290;))