* Power-sharing in Northern Ireland collapsed in January 2017
* DUP leader says talks reached impasse on language rights
* Sinn Fein says rivals could not deliver on tentative deal
* Britain says devolved government best for province (Adds statement from Sinn Fein, British and Irish governments)
BELFAST, Feb 14 (Reuters) - Talks to restart Northern Ireland's power-sharing government broke down yet again on Wednesday, the province's main parties said, blaming each other, though Britain held out hope that a solution could still be reached.
The British province has been without a devolved executive - a central part of a 1998 peace deal that ended three decades of violence - for over a year since Irish nationalists Sinn Fein withdrew from the compulsory power-sharing government with their arch-rivals, the Democratic Unionist Party (DUP).
The long-running talks have also been complicated by the fact that British Prime Minister Theresa May's minority government depends on the support of the DUP to pass legislation in London.
The two parties, representing mainly Catholic proponents of a united Ireland and Protestant supporters of continued rule by Britain, have failed to meet a number of deadlines. They were told last month by the British and Irish governments that they had one last opportunity to reach a deal.
"While substantive progress has been made, it appears this phase of talks has reached a conclusion," Britain's Northern Ireland minister Karen Bradley told reporters.
"The position of the UK government remains the same: devolved government is in the best interests of everyone in Northern Ireland and is best for the union. I believe the basis for an accommodation (between the parties) still exists."
Two days ago the British and Irish prime ministers raised the prospect of the stalemate ending soon. But the talks collapsed when DUP leader Arlene Foster issued a statement on Wednesday saying she saw no current prospect of a deal.
Foster's colleague Simon Hamilton told reporters agreement was "impossible" at this time but that the DUP wanted to pick the talks up at a future date. Foster said it was incumbent on London to set a budget for the region in the meantime.
The British government, which is overseeing the talks alongside the Irish government, has already had to take steps towards ruling the region directly from London for the first time in a decade, setting a budget late last year that runs until the end of March.
Many fear direct rule would further destabilise a delicate balance between nationalists and unionists who, until last year, had run the province since 2007 under the terms of the 1998 Good Friday peace accord that mostly ended decades of sectarian conflict that killed more than 3,600 people.
Sinn Fein said that they had reached an accommodation with the leadership of the DUP that put an agreement within reach but that the DUP failed to close the deal and collapsed the talks. Its leader in Northern Ireland said direct rule was "not an option."
The parties have failed to reach agreement on a number of issues, in particular additional rights for Irish-language speakers which Foster highlighted as the chief reason why they had "reached an impasse".
Sources close to the negotiations told Reuters that some DUP members had issues with the proposed compromise on the Irish language and "robustly raised" their concerns with Foster earlier this week.
The absence of an executive has limited Belfast's say in Britain's negotiations to leave the European Union, which are set to have a bigger impact on Northern Ireland than on any other part of the United Kingdom.
The prospect of direct rule being re-introduced could also trigger a diplomatic dispute over what role the Irish government should have in the region.
Ireland's foreign minister said that as co-guarantors of the 1998 peace deal, both governments have an obligation to uphold the letter and spirit of that agreement and that Dublin must "reflect in the coming days on how best to do that." (Reporting by Amanda Ferguson, writing by Padraic Halpin; Editing by Hugh Lawson and Adrian Croft)