* Not clear if proposals will address uranium enrichment
* Ahmadinejad says Iran won't be bullied
* Diplomat sees no quick lifting of sanctions
By Marcus George
DUBAI, April 11 (Reuters) - Iran will present new proposals at talks on Saturday aimed at easing concerns about its nuclear activity, state television said, but it was unclear if Tehran was willing to address its disputed uranium enrichment drive as six world powers want.
The report did not specify what Iran was set to offer and one Western diplomat said he doubted it would be enough for any quick lifting of sanctions on the Islamic Republic, which the West suspects may be seeking nuclear weapons capability.
"Iran's representatives will participate in the negotiations with new initiatives and we hope that the (six powers) will also enter talks with constructive approaches," said the head of Iran's Supreme National Security Council, Saeed Jalili, according to Iran's English-language Press TV on Wednesday.
Jalili, Iran's chief nuclear negotiator, said Tehran was "ready to hold progressive and successful talks on cooperation" but that "the language of threat and pressure against the Iranian nation has never yielded results".
Previous rounds of talks with the P5+1 group - the five U.N. Security Council members, the United States, Britain, France, Russia and China, plus Germany - foundered in part because of Iran's refusal to negotiate on the scope of its uranium enrichment work, instead floating vague proposals for trade and security cooperation.
Tehran says it is refining uranium solely for electricity and medical treatments. Western states do not believe this and the United States and Israel have not ruled out military action if diplomacy fails to curb Iran's nuclear work.
In Washington, U.S. Secretary of State Hillary Clinton said it was vital Iran come to the talks ready to engage seriously.
"We believe there is still time for diplomacy, but it is urgent that the Iranians come to the table to establish an environment conducive to achieving concrete results through a sustained process," Clinton said as she began talks with the foreign ministers of Britain, Canada, France, Germany, Italy, Japan and Russia, collectively know as the Group of Eight (G8).
The Western diplomat said he did not expect Tehran to offer anything big enough to justify the lifting of a European embargo on Iranian oil that is due to be fully implemented by July 1.
"It would be a surprise if Iran did something that merited moving on that," the diplomat said. "It would need a significant change, I think, from Iran before that kind of alteration to the sanctions regime becomes credible."
OUT OF THE CUPBOARD
On Sunday, the head of Iran's Atomic Energy Organisation, Fereydoun Abbasi-Davani, raised the possibility of Iran suspending enrichment to the 20 percent level of fissile purity if its needs were met.
The proposal did not address Western concerns about what would ultimately happen to Iran's existing reserve of such higher-grade enriched uranium.
Uranium needs to be refined only to up to 5 percent for use in running power plants. A 90 percent threshold is required for atomic bomb material.
Iran says it needs a 20 percent stockpile to fuel a medical isotope reactor. Western powers fear Iran's underlying goal is to advance towards bomb-grade purity and are seeking guarantees via negotiations that this will not come to pass.
The Western diplomat said a previous deal with Iran that would have seen it export some of its enriched uranium in exchange for fuel for the medical reactor still made sense in theory, but would have to be altered to reflect Iran's increasing stockpile of nuclear material.
"On the fuel swap side it isn't really credible to think of just sort of getting out of the cupboard the previous offer. That said, the logic of Iran exporting some, all of, (its) uranium enriched to various levels as one of its confidence building steps, obviously, is a key thing still," he said.
If progress is made, the talks could pave the way to ease sanctions and might lift the threat of an Israeli attack.
President Mahmoud Ahmadinejad said Iran would not be bullied at the talks.
"They constantly insult the Iranian nation and use a language of force against Iranians," state news agency IRNA quoted him as saying at a rally.
"Speaking on behalf of the Iranian nation, I tell them that this method will not work ... and that they should speak with respect."
Iran says it has a sovereign right to uranium enrichment and accuses the nuclear-armed West of hypocrisy and of trying to stifle its technological progress.
Separately, Iran said on Wednesday it had banned imports from 100 European companies to counter Western sanctions.
Sassan Khodaei, deputy head of the state-run Trade Promotion Organisation, said the move was part of a policy to counter "antagonistic measures" by the EU, Press TV reported.
Khodaei said the banned goods included luxury items that Iran can produce itself, but he did not name the goods or their manufacturers.
A report from Press TV on Tuesday said Iran had stopped oil exports to Spain as a pre-emptive measure before the EU embargo comes into force on July 1, but Spain's biggest refiner said it had stopped buying from Iran months earlier.