CAIRO, Nov 27 (Reuters) - Yields on Egypt's three- and nine-month Treasury bills rose at an auction on Sunday, data from the central bank showed.

Yields on the 91-day bill increased to an average of 18.186 percent from 17.744 percent the last time similar bills were sold.

Yields on the 273-day bill jumped to an average of 18.475 percent from 17.610 percent at the last similar auction.

(Reporting by Eric Knecht; Editing by Greg Mahlich) ((Asma.Alsharif@thomsonreuters.com; +20 2 2394 8102; Reuters Messaging: asma.alsharif.thomsonreuters.com@reuters.net))