* Rich urge poor to accept halving of emissions
* "Strong resistance" from China - Berlusconi
(Recasts, updates throughout)
ROME, July 7 (Reuters) - Rich nations sought to persuade China and India on Tuesday to agree to a goal of halving world greenhouse gas emissions by 2050 at a summit of major economies in Italy later this week.
Environment ministers or senior officials from the 17-member Major Economies Forum (MEF) met in Rome, trying to end deadlock over a declaration that could be a step towards a new U.N. climate pact due to be agreed in Copenhagen in December.
"Positions have not shifted," a delegate said of the talks, called at the last minute to help leaders agree a united front on climate change on Thursday in L'Aquila, Italy, during a Group of Eight summit.
China and India have been opposed to a goal of halving world greenhouse gas emissions by 2050 as part of a declaration by MEF nations, which account for 80 percent of world greenhouse gas emissions.
The G8 countries -- the United States, Japan, Russia, Germany, Britain, France, Italy and Canada -- adopted a "vision" of a 50 percent cut in global emissions by 2050 last year and want major developing nations to sign up too.
But developing nations say the rich are to blame for most emissions from burning greenhouse gases since the Industrial Revolution and must set deep 2020 goals for cutting their own emissions before asking for help with 2050 goals.
Italian Prime Minister Silvio Berlusconi also told a news conference that China was resisting progress on the climate.
"Europe wants to be in the vanguard, the Obama administration is in the same position, but there is strong resistance that I have encountered with the Chinese presidency," said Berlusconi, referring to a meeting on Monday.
A June 30 MEF draft drawn up by the United States and Mexico said that: "We support an aspirational global goal of reducing global emissions by 50 percent by 2050, with developed countries reducing emissions by at least 80 percent by 2050."
China and Indian officials have said that poor nations need to be allowed to use more energy to end poverty. China has recently overtaken the United States as top world emitter and India is fourth behind Russia.
If the deadlock persists, U.S. President Barack Obama, who sees the MEF as a step towards a U.N. deal, would end the July 9 meeting with just a "chair's summary" rather than a statement agreed by all 17 MEF leaders.
"Only ambitious action by the G8 could break the deadlock in the negotiations," said Tobias Muenchmeyer of environmental group Greenpeace. He noted that China and India want rich nations to cut emissions by at least 40 percent by 2020 below 1990 levels and far higher climate investments.
A separate climate draft for the G8, dated June 24, indicated progress towards setting a target of limiting a rise in world temperatures to two degrees Celsius (3.6 Fahrenheit) over pre-industrial times.
The European Union views 2C as a threshold for "dangerous" climate changes such as ever more heatwaves, floods, droughts and extinctions. The United States, Russia, Canada and Japan have not signed up for such a target at the G8.
The G8 draft said "global emissions should peak by 2020 and then be substantially reduced to limit the average increases in global temperature to 2 Celsius above pre-industrial levels."
(Editing by Stephen Brown)