Türkiye Is Bankasi AS, Turkey's largest listed bank by assets, has seen its short-term external borrowing costs grow by between 30 and 40 basis points since Turkey's sovereign debt rating was cut to junk, Reuters reported.

Moody's cut the country's rating to noninvestment grade in September 2016, and Fitch did the same in January.

Adnan Bali, Isbank's general manager, told reporters that the impact on borrowing rates is "tolerable."