RBS, Scotland's largest bank and 81 percent-owned by the British government, had said it would relocate south of the border had Scots voted to break their 307 year-old union with England.

The bank's five-year credit default swaps fell 14 basis points from Thursday's close to 65 basis points, according to data provider Markit. That was the lowest since May 2008, a few months before the eruption of the financial crisis that culminated in RBS being rescued by the UK government.

Scottish voters opted to stay in the United Kingdom by a margin of 55 percent to 45 percent.

(Reporting by Jamie McGeever)