Sanctions on Iran tighten their grip with European measures to make business with the Opec member even harder, but no-one expects its oil trade to cease as high profits and energy needs inspire ingenuity, said experts.

Following US sanctions and in anticipation of the EU action, oil markets have been awash with talk of reduced gasoline imports to Iran, higher costs and doubts its crude exports can be paid for in the euro and the US dollar under the new regime.

Iran - the world's fifth largest oil exporter - is used to finding a way. "The point is the sanctions are not new. The shape is different. We can carry on," Iran's Opec governor Mohammad Ali Khatibi said in a telephone interview.

EU foreign ministers were meeting on Monday to approve formally new measures, adding to US rules that also target Iran's energy industry. "We have a comprehensive set of sanctions," EU foreign affairs chief Catherine Ashton told reporters.

Short-term imports of refined products, which make up for Iran's lack of domestic refining capacity, will be disrupted as Iran navigates the new sanctions and the rest of the world grapples with the complexities of interpretation, analysts say.

Looking to the long term, even the new sanctions are unlikely to be airtight. Analysts also note Iran's oil industry has strengths, but would benefit from international help.

"Without a shadow of doubt, they're having an impact, but are sanctions a disaster? No," said Colin Lothian of Wood Mackenzie consultancy.

"The Iranian oil industry is a very capable sector. However, it may never reach its aspirational goals without the assistance and investment of the international upstream community."

For many companies, Iran has long been just too testing an environment for little reward. The nation is struggling to halt decline rates of around 8-10 percent at mature fields and almost every project has suffered delays.

For years, there has been uncertainty about the long term and that is only aggravated by the latest measures. Gas, as well as oil production, and domestic refining capacity need to increase to meet domestic demand and free up crude oil for export.

Oil markets have been well-supplied since the world tipped into recession stifling demand, meaning everyone can be relaxed about any disruption of Iranian crude, but only for now.

With an eye to its huge future energy needs, China has a reputation for involvement in oil-producing territory other nations avoid. A major customer of Iran's crude, a supplier to Iran of refined products and a project partner, it is expected to carry on doing business whatever the difficulties.

"They will still try to keep a presence and keep operating within the confines of the sanctions," said Lothian. Other friendly powers also have an interest in continued involvement, although even they have adopted a cautious tone.

Russia, which together with China, held the UN back from the kind of tougher, energy-targeted sanctions being implemented by the E.U. and US, soothed Iran with talk of energy co-operation.

At the same time, it urged it to explain the "military components" of its nuclear programme. Russia could be particularly nervous of risking ties with its European customers.

But the holder of the world's largest gas reserves also has an interest in maintaining a connection to Iran, which holds the second largest gas reserves and has the potential to supply the Nabucco pipeline - Europe's big project to reduce its dependency on Russian gas supplies.-Reuters