The deputy leader of the pro-independence Scottish National Party, Nicola Sturgeon, effectively conceded defeat in the vote after the bulk of results had leant towards "No".

Sterling, already pushed up on Thursday by speculation on markets that Alex Salmond's nationalists had fallen short of the majority needed to break up their union with England, gained another half percent to as high as $1.6525.

London blue chip futures pointed to a 1.2 percent rise when markets open later on Friday, while the cost of insuring against big swings in Britain's pound over the next week sank to 7.087 percent from a close on Thursday of 11.8 percent.

(This version of the story corrects name of politician in second paragraph)

(Reporting by Sudip Kar-Gupta, Patrick Graham and Jamie McGeever)