CAIRO, July 24 (Reuters) - Yields on Egypt's three-month and nine-month treasury bills rose at Sunday's auction, data from the central bank website showed.

The average yield on the 91-day bill rose to 14.272 percent from 14.149 percent at the last auction on July 17. The 273-day bill slightly rose to 15.752 percent from 15.570 at a similar auction a week ago.

(Reporting by Ola Noureldin, editing by Louise Heavens)