By Evelyn Leopold and Michelle Nichols

UNITED NATIONS (Reuters) - Six major powers announced an agreement on Thursday to impose new U.N. sanctions on Iran for its nuclear program, but Iranian President Mahmoud Ahmadinejad vowed the initiative would not sway his country.

U.N. Security Council for a potential a vote next week. It would penalize Tehran for refusing to suspend uranium enrichment, which can be used in nuclear bombs or for peaceful ends.

Iran says it seeks only to produce electricity, and Ahmadinejad denounced any new U.N. sanctions resolution.

"Issuing such torn pieces of paper ... will not have an impact on (the) Iranian nation's will," he told a rally in central Iran, according to the official news agency, IRNA.

Britain's U.N. Ambassador Emyr Jones Parry announced the agreement after consultations with his counterparts from the United States, France, Russia, China and Germany.

The proposed Security Council resolution includes a ban on Iranian arms exports, an assets freeze on individuals and firms involved in Tehran's nuclear and ballistic missile programs and a call to nations and institutions to bar new grants or loans. A copy of the document was obtained by Reuters.

A key element of the agreement is an expanded list of individuals and entities subject to financial restrictions, such as firms owned by Iran's Revolutionary Guards Corp. and the state-owned Bank Sepah.

China's U.N. Ambassador Wang Guangya, who had been most critical of the list, was asked if Beijing was happy with the draft. "As the text stands, yes," Wang said, adding that if the 10 rotating council members "wish to change it then we have to go back again"

In Washington, State Department spokesman Sean McCormack said the resolution may be subject to additional minor changes but he believed it would move along "as quickly as possible."

European Union foreign policy chief Javier Solana said he expected adoption of a new resolution would be accompanied by a reminder to Tehran that it could always return to negotiations if it suspended enrichment. "They know what they have to do," he told reporters in the German city of Nuremberg.

The new measures follow a resolution adopted in December that imposed trade sanctions on Iran's sensitive nuclear materials and technology, and froze the assets of some Iranian individuals and companies. Iran ignored a February 21 deadline to suspend enrichment or face further action.

The agreement comes only days after the mutually wary United States and Iran participated, along with Syria and  Iraq, in Baghdad talks on quelling sectarian violence in Iraq, which Washington accuses Tehran of fomenting.

It also comes a month after North Korea agreed in talks with the United States, China, South Korea, Japan and Russia to take steps toward abandoning its nuclear programs -- another Bush administration goal in nuclear diplomacy.

Passage of a new resolution by the 15-member council is not automatic. South African Ambassador Dumisani Kumalo, the current council president, has served notice that nations would send the text to their governments for approval and may offer changes.

U.S. deputy U.N. ambassador Alejandro Wolff said the text was not perfect but that "I'm satisfied with the compromise outcome."

The agreement says Iran is banned from exporting any conventional weapons. But the measure calls on states to "exercise vigilance and restraint" in shipping any heavy weapons to Tehran.

The draft would suspend all the sanctions if Iran complies with the council's demands within 60 days. If Tehran does not, further action would be considered.

There is no mandatory travel ban on individuals on the list, but nations would be required to notify a Security Council panel if the targeted officials enter their territories.

All sanctions would be suspended if Iran complies with the council's demands within 60 days. If Tehran does not, further action would be considered.