LONDON- The cost of insuring exposure to Turkish debt rose on Monday to a 12-day high as the banking regulator was forced to dismiss a weekend report that some of the country's lenders face substantial U.S. fines for Iran sanctions evasion.

Data from IHS Markit showed that five-year credit default swaps (CDS) for Turkey rose 4 basis points (bps)to 177 bps, the highest level since October 11. The lira TRY= and Turkish banking stocks .XBANK fell.

Relations between NATO allies Washington and Ankara have been strained by a series of diplomatic rows.

(Reporting by Karin Strohecker, editing by Mike Dolan) ((karin.strohecker@thomsonreuters.com; +442075427262; Reuters Messaging: karin.strohecker.reuters.com@reuters.net))