LONDON, July 17 (Reuters) - U.S. company Westinghouse said South Korea's KHNP is not authorised to use its reactor technology for a tender to build Czech nuclear projects without its agreement.

"Westinghouse reserves its rights to challenge this in front of the relevant national and international jurisdictions," it said in an emailed statement.

(Reporting by Susanna Twidale Editing by David Goodman )