* Attempt to relaunch budget talks ends in failure - NRK
* Minority government unable to win backing for 2017 budget
* Prime minister may ask for vote of confidence (Updates with report of talks ending)
OSLO, Dec 2 (Reuters) - Norway's minority right-wing government failed to rekindle deadlocked negotiations over next year's budget on Friday, just two days after the previous round of talks collapsed, public broadcaster NRK reported.
The government of the Conservatives and the Progress Party must obtain support from either the Christian Democrats or the Liberal Party by Monday to win a majority in parliament for a spending plan, or otherwise risks having to step down.
Conservative Prime Minister Erna Solberg met with the leaders of the two centrist parties early on Friday to offer new concessions, but to no avail.
With a sovereign wealth fund worth $858 billion, more than twice Norway's annual gross domestic product, the key debate is not over how much money to spend but rather how to compromise on the four parties' conflicting policy goals.
There are big differences, for example, over petrol and diesel taxes, which the centrists want to raise sharply to help cut greenhouse gas emissions, while the government has only agreed to a small increase.
Without support for a budget, Solberg may ask parliament for a vote of confidence, a rarely used last-ditch measure to prevent a government collapse.
As early elections are not permitted under Norway's constitution, and the next vote is not due until September 2017, the Christian Democrats are seen by some analysts as a potential white knight that may help a weakened government stay in power.
But if a confidence motion were to fail, it would force Solberg to resign and trigger a complex round of talks to determine whether or not the main opposition Labour Party should replace the coalition. (Reporting by Joachim Dagenborg, writing by Terje Solsvik; Editing by Mark Trevelyan)