VIENNA (Dow Jones/Bloomberg) — Iran formally offered 17 onshore and offshore oil blocks for development at a conference in Vienna that attracted many non-U.S. international oil companies despite rising international pressure on Tehran over its nuclear program.

Five of the blocks are offshore, according to Dow Jones.

"NIOC has ambitious plans to expand its production over the next decade both onshore and offshore," Gholam Hossein Nozari, Iran's deputy oil minister and the managing director of the state-run National Iranian Oil Co. (NIOC) said.

Conference participants include officials from companies such as China Petroleum & Chemical Corp. (SNP), or Sinopec, Austria’s OMV AG, Norway's Statoil ASA (STO), Royal Dutch Shell PLC (RDSB.LN), Italy's ENI SpA (E), France's Total SA (TOT) and Russia's Lukoil (LKOH.RS).

Iran says threats aren't affecting energy investment

OMV AG is leading efforts to build the €5 billion Nabucco project, Bloomberg reported. “There's a great amount of interest,” National Iranian Oil Company Managing Director Gholam Hossein Nozari said on Thursday at a conference in Vienna.” There are many countries here.” Iran needs about $94 billion of foreign investment by 2014 to maintain production rates, Nozari said. The country is losing about 7% of production annually because of depletion, he said. “ Lukoil is very serious about developing oil and gas projects in Iran,” said Andrey Kuzyaev, the president of Lukoil Overseas Holding Ltd. We're trying to expand our activities there.”

Moscow-based Lukoil, Russia's biggest oil company, is planning to drill two exploratory wells next year in Iran's northern Caspian basin, Kuzyaev said. Iran is sweetening exploration contracts to attract more bidders by reducing risk, Nozari said. The country will double the time private companies can expect to make money on oil discoveries to around 15 years.

Iran is also ready to fix capital expenditure costs for companies ready to invest. The 17 exploration tenders will attract at least €460 million ($598 million) in investment, according to published guidelines. Companies must submit proposals by June 20. “Iran would be the ideal partner for us,” said OMV's exploration chief, Helmut Langanger.”

“No company can afford to not look at Iran. There are still enormous reserves to be discovered and exploited in the future.” OMV is developing an oil block along with Repsol on the Iranian side of the Iraq border, Langanger said. The Austrian company is leading efforts to build the €5 billion Nabucco project, a pipeline that may transport gas from Iran to Europe.

The world’s biggest oil companies attended the two-day meeting despite the Bush administration's pressure on European oil and gas companies against investing in Iran, Washington Post reported on Thursday.

In the past two weeks, the administration has met with European oil company executives about the Middle East, and during one session a senior State Department official cautioned that the situation with Iran was "hot and is going to get hotter," one executive said.

An executive from a major European company said, "The administration is putting the full-court press on foreign companies and is going all out to impress upon them that it would be a mistake to do anything with" Iran. "Obviously Iran is very interesting oil territory for everybody," said Patricia Marie, spokeswoman for the French oil company Total S.A., which invested about $4 billion in Iran between 1995 and 2002 and sent a representative to the meeting. As for U.S. admonitions, Marie said, "We are listening. . . . But we respect the French law, the European laws; we are not obliged to respect American law."

Marie said Total will decide this year whether to proceed with a liquefied natural gas (LNG) project in the south of Iran.

Last week, Royal Dutch Shell and the Spanish company Repsol YPF S.A. signed a preliminary agreement with Iran to explore the possible development of another multibillion-dollar LNG project.

One international executive said Iranians usually offer single-digit rates of return for investments in the oil sector, far less than what companies can make elsewhere. "The Iranians always argue that there is no need for them to offer more because of the very low geological risk in Iran, because they know it's a country with substantial reserves," he said. "But you have to factor in political risk and all sorts of other things."

The struggle over oil investment is part of the Bush administration's campaign to isolate Iran and curtail its funds because of its pursuit of nuclear technology.

U.S. companies are barred from doing business with Iran. In 1995, an executive order stopped them from even bringing Iranian oil to Europe. In 1996, Congress passed the Iran-Libya Sanctions Act, enabling the U.S. government to sanction foreign firms doing business with Iran. Though the United States has issued waivers to European companies involved in Iran's oil sector, one European executive said the Bush administration might change that stance.