* Scotland to hold independence vote on Sept. 18
* Polls show voters are likely to say no
LONDON Feb 2 (Reuters) - The number of people in Scotland who want their small country to become independent of the United Kingdom in a referendum later this year has risen slightly, a poll showed on Sunday, but those opposed to a breakaway still enjoy a commanding lead.
In the referendum, to be held on Sept. 18 this year, voters will decide whether Scotland, which has a population of just over 5 million and is a source of North Sea oil, should end its 307-year-old union with England and leave the UK.
A "yes" vote would place the future of Britain's Scotland-based nuclear submarine fleet in doubt and could weaken London's claim to a permanent seat on the United Nations and its influence in the European Union.
The poll, carried out in January by TNS BMRB in more than a 1,000 face-to-face interviews, showed support for independence at 29 percent, up three points from 26 percent in November in a similar TNS poll.
But it showed support for Scotland remaining part of the UK was steady at 42 percent, the same as in November, suggesting Scots will reject independence. The number of undecided voters was 29 percent.
Surveys carried out by other pollsters have put the "no" camp's support considerably higher. A YouGov poll in December put the "no" camp on 52 percent to 33 for the "yes" camp, while a poll for Ipsos-Mori put the "no" camp on 57 percent and the "yes" camp on 34.
Tom Hunter, a Scottish millionaire property tycoon who commissioned Sunday's poll, said he thought there was a dearth of information to help Scots make an informed choice, a view backed by 56 percent of voters in the same survey.
"It is my belief that the referendum is way closer to call than anyone thinks and for that reason I believe many Scots need far more data and evidence in order to make an informed choice," Hunter said in a statement.
Hunter, who launched a website which he said would provide that information, said he was not seeking to influence the outcome of the vote either way and would not be revealing his own voting intention at any time. (Reporting by Andrew Osborn; Editing by Andrew Roche)