Pakistan warned major powers on Tuesday against granting rival India membership of four key multilateral export control regimes that allow trade in nuclear and other materials, as proposed by the United States.

The plan, announced during U.S. President Barack Obama's visit to India last November, would further destabilise the volatile nuclear-armed South Asian region, said Zamir Akram, Pakistan's ambassador to the United Nations in Geneva.

This reinforced Pakistan's opposition, announced a year ago, to global negotiations to ban future production of nuclear bomb-making material, he said.

These developments will amount to a paradigm shift in strategic terms, Akram said in a speech to the opening session of the U.N.-sponsored Conference on Disarmament.

The message that such steps transmit is that the major powers can change the rules of the game if it is in their interest to do so, he added.

Pakistan is the only one of 65 member states holding up consensus to launch the fissile talks, arguing that existing stocks of plutonium and enriched uranium should be included to counter its neighbour's advantage.

The United States clinched a civilian nuclear deal with India in 2008, ending its nuclear isolation and granting it access to nuclear fuel and technology while allowing it to continue its nuclear weapons programme.

The Obama administration has announced backing for Indian membership of four regimes: the Nuclear Suppliers Group, the Missile Technology Control Regime, the Australian Group, which aims to reduce the spread of chemical and biological weapons, and the Wassenaar Arrangement, a multinational effort to control the transfer of conventional arms and dual-use technology. [

Apart from undermining the validity and sanctity of the international non-proliferation regime, these measures shall further destabilise security in South Asia, Akram said.

The 46-nation Nuclear Suppliers Group tries to ensure that nuclear exports are not diverted for military purposes.

But Pakistan's envoy said that membership would enable India to improve its nuclear weapons and delivery capability.

As a consequence, Pakistan will be forced to ensure the credibility of its (nuclear) deterrence, Akram added.

The United States said on Monday it was easing curbs on exports of high-tech goods to India in recognition of the two countries' stronger economic and security ties.

Pakistan, tainted by revelations that disgraced top scientist A.Q. Khan had run a nuclear smuggling ring that helped Iran, North Korea and Libya, has turned to ally China for help.

But Akram made no reference to China's offer to build two new nuclear powered reactors for Pakistan at its Chashma complex -- which have raised global concern about nuclear proliferation.

To import nuclear goods, all nations except the five officially recognised atomic weapons states must usually place nuclear sites under safeguards of the International Atomic Energy Agency, the U.N. nuclear watchdog, NSG rules say.

When the United States sealed its nuclear supply accord with India in 2008, it won a waiver from such NSG rules.

India and Pakistan -- which have fought three wars -- have both refused to sign the nuclear Non-Proliferation Treaty (NPT) that bars nuclear trade with states that have developed weapons. Both have built modest nuclear arsenals with India believed to hold about 100 warheads and Pakistan 70 to 80, according to the Washington-based Arms Control Association

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