* First minister says Scotland would be "enthusiastic" EU member
* Salmond says expects fast negotiations over its EU membership
* Oil-rich Scotland wants Europe but not euro
BRUGES, Belgium, April 28 (Reuters) - An independent Scotland would be a more constructive member of the European Union than a reluctant Britain, Scottish first minister Alex Salmond said on Monday.
He believed EU members would welcome an "enthusiastic" Scotland into the bloc should it vote to end the 307-year-old union with England in a referendum on Sept. 18, he said.
Remaining part of the EU is fundamental to the nationalists' vision of an economically viable independent Scotland. However, European Commission President Jose Manuel Barroso has said Scotland would have to reapply to the EU as a new state.
Spain, which faces Basque and Catalan separatist movements, also opposes automatic membership to the 28-nation bloc.
Salmond took his campaign to Bruges in Belgium on Monday, seeking to persuade Europeans that keeping Scotland within the EU fold was very much in their own interest.
In a speech, he said Scotland's energy reserves and fishing grounds would make it a crucial EU member.
Speaking later to Reuters, he pointed out that while Scotland wanted to stay part of the EU, British Prime Minister David Cameron has promised to renegotiate ties with the EU and hold a referendum on Britain's membership if his Conservatives win a general election next year.
"The difference in Westminster, is that there is lots and lots of people who see the abolition of Europe, drifting off into the mid Atlantic, as a viable option," Salmond said in an interview.
"The real threat to Scotland in Europe is not from an independent Scotland. It's from the in-out referendum that Westminster are proposing."
Speaking of his concern that Scotland "could be dragged out of the European Union against our will", he said his country's stance was more constructive.
"People welcome the attitude that we have...we are not talking about taking our toys and stomping off."
Salmond, who heads the ruling Scottish National Party, said that should Scots choose to break away from the United Kingdom, he expected it would be possible to negotiate EU membership before a formal declaration of independence in March 2016.
But he said Scotland would not join the euro currency zone.
All new EU member states are required to sign up to joining the common currency at some future date.
"You cannot be forced compulsorily to be in the euro," Salmond said. "It's a voluntary thing. Because England is our biggest market, we should stick with sterling."
The British government and the three main UK political parties have insisted that an independent Scotland could not retain the pound or use the Bank of England as its central bank.
His speech, at the same venue where former British Prime Minister Margaret Thatcher criticised centralisation of power in Brussels in 1988, was made as opinion polls show the gap between the two sides narrowing to a few percentage points.
The polls suggest Scotland, home to 5.3 million of the United Kingdom's 63 million people, will vote narrowly in favour of the status quo. But the independence campaign is gaining ground.
Salmond argued in his speech that Scotland is vital for energy security in Europe with 25 percent of its offshore wind and tidal potential and 60 percent of the EU's oil reserves.
"We have one of the largest national shares of Europe's total fishing grounds and 12 national fleets fish in our waters. The EU's fisheries policy would unravel without Scotland," he said.
He also said that 160,000 people from other EU states live in Scotland.
British Foreign Secretary William Hague told Salmond that Scotland would face lengthy and difficult negotiations to stay in the EU and would end up worse off than at present.
"The terms of EU membership which your government has said it will seek to secure for an independent Scotland are at odds with the EU's own rules of membership," he wrote in a letter.
"The people of Scotland would be swapping the guaranteed negotiating power of one of the EU's most powerful states for the hope of goodwill from 28 others - and with a much higher price tag - a poor substitute indeed," Hague said. (Reporting By John O'Donnell; Editing by Angus MacSwan)