Scotland’s decision to remain part of the United Kingdom in an historic referendum Friday gave British markets a brief lift, as fears of an independent Scotland causing economic havoc waned.

After an unprecedented voter turnout of just under 85 percent, 55.3 percent were against independence to 44.7 percent in favor. The decision prevented a rupture of a 307-year union with England, Wales and Northern Ireland.

Investors breathed a sigh of relief that the vote didn’t spark economic woes, including questions over what currency an independent Scotland would use and how the U.K.'s 1.3 trillion pounds ($2.1 trillion) debt would be divided. The FTSE 100 index of leading British shares ended up 0.3 percent at 6,837.92 but had been higher earlier in the session.

Uncertainty over the pound was likely a key element in the No campaign's victory. The Yes campaign had hoped it would still use the pound through a currency union with what's left of the U.K. but the main British political parties insisted that wasn't going to happen. There were also fears that a Yes vote may have triggered a bank run.

"It might not have been financial meltdown territory, but the markets almost certainly would have been in turmoil if the Scots had voted yes," said Dennis de Jong, managing director at UFX.com.

More On This... Scotland votes on independence referendum

Prime Minister David Cameron promised new powers for Scotland in the wake of the vote, but also warned that millions of voices in England must also be heard, calling for a “balanced settlement” that would deliver more power to the United Kingdom.

“Like millions of other people, I am delighted,” Cameron said in a speech outside 10 Downing Street on Friday morning. “It would have broken my heart to see our United Kingdom come to an end.”

The result sparked the resignation of Scotland's pro-independence leader, Alex Salmond, who said Friday that he is resigning as first minister and leader of his Scottish National political party.

Salmond, 59, told reporters at a news conference that he was proud of the campaign and the record turnout for Thursday's vote.

"For Scotland the campaign is not over and the dream will never die," he said.

Queen Elizabeth II was expected to give a statement Friday afternoon, Sky News reported.

“The people of Scotland have spoken,” Alistair Darling, leader of the “Better Together” campaign said early Friday after the result was confirmed. “We have chosen unity over division.”

Despite major victories for the “Yes” campaign in Dundee and Glasgow, a majority of voters did not embrace Scottish First Minister Alex Salmond's impassioned plea to launch a new state, choosing instead the security offered by remaining in the United Kingdom.

Salmond conceded defeat, saying "we know it is a majority for the No campaign" and called on Scots to accept the results of the vote.

He said the vote "has been a triumph for the democratic process."

Salmond had argued that Scots could go it alone because of its extensive oil reserves and high levels of ingenuity and education. He said Scotland would flourish on its own, free of interference from any London-based government.

Nonetheless, the skilled 59-year-old leader of the Scottish National Party came close to winning independence -- his long-cherished goal -- and still won a promise of new powers for Scotland from rattled London politicians.

Many saw it as a "heads versus hearts" campaign, with cautious older Scots concluding that independence would be too risky financially, while younger ones were enamored with the idea of building their own country.

The result saves Cameron from a historic defeat and also helps opposition chief Ed Miliband by keeping his many Labour Party lawmakers in Scotland in place. His party would have found it harder to win a national election in 2015 without that support from Scotland.

For his part, Cameron -- aware that his Conservative Party is widely loathed in Scotland – had previously begged voters not to use a vote for independence as a way to bash his party.

The vote against independence keeps the U.K. from losing a substantial part of its territory and oil reserves and prevents it from having to find a new base for its nuclear arsenal, now housed in Scotland. It had also faced a possible loss of influence within international institutions including the 28-nation European Union and the United Nations.

The decision also means Britain can avoid a prolonged period of financial insecurity that had been predicted by some if Scotland broke away.

In return for staying in the union, Scotland's voters have been promised significant -- though somewhat unspecified -- new powers by the British government, which had feared losing Scotland forever.

Labour MP Jim Murphy, who played a key in the Better Together campaign, told Sky News that it was now time to make a success of Scotland’s decision.

"While I'm delighted, there is no time or space for triumph and we have got to get on and offer that devolution package we offered and unite the country around that,” Murphy said.

The Associated Press contributed to this report.