* EU says plan for new deal by 2015 gaining traction
* China move may put pressure on United States, NGO says (Adds details, quotes)
By Stian Reklev
DURBAN, Dec 2 (Reuters) - China gave U.N. climate talks a lift on Friday by confirming it may sign up to a legally binding deal to cut emissions of heat-trapping gases, a move that could help rescue talks about the future of the Kyoto Protocol, observers said.
Delegates from more than 190 nations are in the coastal city of Durban to try to break a four-year deadlock to secure a new global deal that will bind countries to cut and slow down growth in emissions of six main greenhouse gases.
"We do not rule out the possibility of legally binding. It is possible for us, but it depends on the negotiations," Su Wei, China's lead negotiator, said - speaking in English - at a media briefing on the sidelines of the two-week talks in South Africa.
The EU has said it will sign up to a second round of targets under the 1997 Kyoto Protocol, but only if all big emitters agree legally binding cuts that will start in 2020.
So far, China, India and the United States, the world's top three emitters, are not bound by Kyoto and have refused to commit to legal targets, raising the prospect that no country will have targets to cut emissions after 2012.
"Since the EU is the only group of parties that is ready to consider a second commitment period (under Kyoto) we are ready and willing to engage constructively with the EU," said Su.
Li Yan, a campaigner with Greenpeace China said, "China is trying to find a middle ground, especially with Europe, which would need to reconcile with China's priorities for the conference, which are a second commitment period of the Kyoto Protocol and operationalisation of the Green Climate Fund."
China wants negotiations to kickstart a fund that would contribute to raising $100 billion a year by 2020 to help the poorest nations adapt to climate change and cut their emissions.
Time is running out to reach agreement on a deal for meaningful cuts in the emissions blamed for worsening storms and raising sea levels to a point that would wipe out several small island states, experts said.
Earlier in the day, senior EU negotiator, Tomasz Chruszczow, said the bloc's plan to have a deal in place by 2015 and entering into force in 2020 was "getting traction".
China has previously said it supported legal targets for others, but not for itself.
Oxfam senior climate change advisor, Kelly Dent said, "This increases the pressure on the U.S."
U.S. lead negotiator, Jonathan Pershing, told journalists earlier in the day that the world's No. 2 emitter would not take on legally binding cuts because it did not believe that major emerging economies would do so.
The talks end on Dec. 9 and South Africa's President Jacob Zuma signalled the host is looking for a deal that puts more of an onus on rich nations to cut greenhouses gases than the developing nations most harmed by rising temperatures.
Canada and Russia have bluntly refused to sign another target under Kyoto, while Japan on Friday asked for a fresh look on a new treaty that encompasses all major emitters.
"We made a concrete proposal to set up a working group where we start discussing a new international framework," Masahiko Horie, Japan's ambassador for global environment, told Reuters.
Christiana Figueres, the U.N. climate chief, told journalists that a new negotiating text would emerge over the weekend after delegates had "literally worked day and night".
Negotiators said the outline of the EU plan offers a political cushion for many countries by setting 2015 as a deadline for a new deal, which would be implemented by 2020.
Meanwhile, negotiators from small island states most at risk of rising sea levels want a new deal to start in 2013, although observers say this is highly unlikely to happen.
Envoys could say they made progress in Durban by agreeing to an encompassing agreement, leaving the details of how the deal would work to a later date. (Additional reporting by Michael Szabo and Jon Herskovitz; Writing by Andrew Allan; Editing by Louise Ireland)