Hoping to avoid a U.N. showdown, Iran (search) and the European Union's three big powers reached a preliminary agreement over Tehran's nuclear program, Iran's chief negotiator said Sunday.

Meanwhile, lawmakers in Iran's conservative-dominated parliament pushed for a bill banning the production of nuclear weapons in a gesture of building more international trust.

The preliminary agreement worked out in Paris with Britain, France and Germany could be finalized in the next few days, chief Iranian negotiator Hossein Mousavian told state-run Iranian television from the French capital, where talks wrapped up Saturday.

If approved, the deal would be a major breakthrough after months of threats and negotiations and could spare Iran from being taken before the U.N. Security Council (search), where the United States has warned it would seek to impose economic sanctions unless Tehran gives up all uranium enrichment activities, a technology that can produce nuclear fuel or atomic weapons.

The head of the Vienna-based International Atomic Energy Agency, Mohamed ElBaradei (search), called the agreement "a step in the right direction."

ElBaradei, speaking on the sidelines of an international conference on nuclear security in Australia, said he hoped the deal would be finalized in "the next few days" and would lead Iran to suspend its nuclear enrichment and reprocessing programs.

Diplomats in Austria familiar with the talks outcome declined to discuss details. "One or two points remain outstanding, and they hope to resolve those outstanding points by Wednesday," one diplomat in Austria told The Associated Press.

In proposals to Iran last month, Britain, Germany and France offered a trade deal and peaceful nuclear technology — including a light-water research reactor — if Iran pledged to indefinitely suspend uranium enrichment and related activities such as reprocessing uranium and building centrifuges used to enrich it.

Europe and Washington fear Iran is trying to build nuclear weapons, but Tehran denies such claims, saying its atomic program has peaceful aims, including energy production.

"We had 22 hours of negotiations ... They were very difficult and complicated negotiations but we reached a preliminary agreement at the expert level," Mousavian said. He said the four countries must now ask their governments to approve the accord.

The preliminary agreement appeared to mark a dramatic breakthrough, since Iranian officials have resisted indefinite or long-term suspension of nuclear enrichment, a process that Iran is permitted to pursue under the Nuclear Nonproliferation Treaty, which Tehran has signed.

While not being in breach of the treaty, Iran is under heavy international pressure to drop such plans as a good faith gesture.

"If this is approved by all four parties, we will witness an important change in Iran's relations with Europe and much of the international community in [the] not-too-distant future," Mousavian said without elaborating on the agreement.

The Europeans had warned Iran that they will back Washington's threat to refer the Islamic republic to the U.N. Security Council for possible sanctions unless it gives up all uranium enrichment activities before a Nov. 25 meeting of the U.N. nuclear watchdog in Vienna.

Tehran suspended uranium enrichment last year but has refused to stop other related activities such as reprocessing uranium or building centrifuges, insisting its program is intended purely for the production of fuel for nuclear power generation.

Meanwhile, lawmakers "are collecting support for a draft bill banning the production of nuclear weapons," legislator Mohmoud Mohammadi told the AP.

Mohammadi, a former Foreign Ministry spokesman, said the bill could be presented to the parliament next week, adding that the draft was prompted by a religious verdict by Iran's supreme leader, Ayatollah Ali Khamenei.

Khamenei, who has the final say on all state matters, has said that production, stockpiling and using nuclear weapons was un-Islamic and against human interests.

"Ayatollah Khamenei's verdict is clear," Mohammadi said. "So why not make the production of nuclear weapons illegal under Iranian law?"