CHICAGO (Reuters) - CKE Restaurants Inc (CKR.N: Quote, Profile, Research), operator of fast-food chains including Carl's Jr. and Hardee's, on Wednesday said sales at established restaurants rose 1.7 percent during the four weeks that ended April 21.

The company said sales at Carl's Jr outlets open at least 13 months were up 3.8 percent, compared with a 2.2 percent increase in the same period last year.

However, Hardee's same-store sales fell 0.8 percent, compared with a 2.4 percent increase in the year-ago period.

Revenue from company-operated Carl's Jr restaurants, excluding franchise-related revenue and royalties, was about $49.3 million, the Carpinteria, California-based company said. Revenue from company-operated Hardee's restaurants was about $41.4 million.

(Reporting by Ben Klayman; Editing by Maureen Bavdek)