* Populous, resource-rich Iran could be lucrative market
* German exports to a post-sanction Iran could hit 5 blneuros
* German-Iranian Chamber of Commerce reports increasedinterest
* Many companies eyeing opportunities, but too early to act
By Alexandra Hudson
BERLIN, Nov 29 (Reuters) - The phone hasn't stopped ringingat the German-Iranian Chamber of Commerce since six world powersreached a deal with Tehran to curb its nuclear programme,opening the prospect that Iran can begin to shake off itseconomic isolation.
A strategically located country with massive oil and gasreserves, an urgent need to overhaul its creakinginfrastructure, and a young population of 76 million is ofparticular interest to export champion Germany, once Iran'slargest trade partner.
"We are speaking to companies interested in doing businesswith Iran all day," said Michael Tockuss, director of thechamber of commerce.
In practice, they are likely to tread warily. Thepreliminary accord struck in Geneva on Sunday,which brings up to $7 billion worth of sanctions relief to Iran,could still come unstuck after 10 years of distrust and rancour,leading to yet deeper sanctions that could sink any hastyinvestments.
The deal, which runs for six months, includes access to apotential $1.5 billion in trade in gold and precious metals, thesuspension of some sanctions on Iran's auto sector andpetrochemical exports, and opens ways to send and receivepayments for humanitarian trade, including medicine and medicaldevices.
The United States, under pressure from congressmen scepticalabout the deal and from an implacably opposed Israel, hasdownplayed the likelihood of a business bonanza.
"We don't see on the basis of a six-month agreement businessrushing in ... and we will vigorously, vigorously, enforce thevast majority of sanctions, which will remain in place," asenior U.S. administration official said ahead of the talks.
But he conceded: "There is no doubt that some business willreturn to Iran."
Tockuss said there was "not only appetite from Germany.American firms are also very interested, particularly in areassuch as medical equipment ... One of the most important aspectsof the agreement is the financial channel it establishes."
He also listed automobile parts suppliers, machinery makersand infrastructure suppliers as firms that could benefit.
Although humanitarian products like medicines were exemptfrom sanctions, in practice supplies have been disrupted becausebanks and companies have been wary of doing business withTehran. That could now start to change, increasing the flow ofWestern drugs to the country.
Richard Bergstrom, director general of the EuropeanFederation of Pharmaceutical Industries and Associations, said controls on capital flows had indirectly contributed toshortages of medicines in Iran. "I think the easing ofrestrictions is good for Iranian patients," he said.
Turkey's leading pharmaceuticals company Abdi Ibrahim saidthe ability to resume payments under a Turkish bank would be apositive driver for companies.
"Our team has been analysing the Iranian market for sometime, but due to latest developments we'll speed up theprocess," said chairman Nezih Barut. "We are expecting to startproduction by the end of 2014 at the earliest and maybe by2015."
Germany's largest companies were mostly tightlipped. Autosand machinery maker MAN said it had no business withIran and no plans to change that. Conglomerate Siemens said it would fulfil existing contracts, but notestablish new business.
A spokeswoman for conglomerate Robert Bosch, a bigsupplier to the auto industry, acknowledged there was goodpotential if the political and legal conditions held up, givenIran's central location, big young population and decenteducation levels.
She said Bosch had no facilities in Iran and closed a Tehranoffice in 2010, but was monitoring the situation closely andexamining prospects for possible business there.
Deutsche Bank said it was too early to say.
"There is no fundamental sense of relief that we can take onnew business deals in a big way," said co-chief executiveJuergen Fitschen, but added that once trade picked up,cross-border transactions would need banks.
Turkey's banks were already getting the green light fromtheir government.
"Because of the pressure exerted by the United States,private banks were unable to process (Iranian) transactions. Nowthat obstacle has been removed, not only Halkbank but otherbanks will be able to process payments," Economy Minister ZaferCaglayan told reporters in Istanbul.
REVIVING TIES
Other European companies were watching with interest.
"From a practical point of view, if these sanctions againstIran were to be eased, that could mean positive possibilitiesfor the Volvo Group," said a spokeswoman for the Swedish truckmaker. "That is obvious."
French building materials firm Saint-Gobain wastaking the long view.
Asked if the deal with Tehran opened new opportunities,co-chief executive Pierre-Andre de Chalendar said: "In due time,I sure hope. But it is a bit early to say."
While some firms are looking for new openings, South Africanmobile phone operator MTN Group has unfinished businessit hopes to settle; it has about $450 million locked in its Iranunit, frozen by the sanctions.
Similarly, a full-scale lifting of sanctions could allowAustrian energy firm OMV to revive a major 2007 gasexploration and production deal with Iran, which it had to puton ice because of political pressure.
The agreement foresaw OMV and the National Iranian OilCompany jointly producing liquefied natural gas from the world'sbiggest gas field, South Pars, as well as OMV's buying gas fromIran for Europe. An OMV spokesman said the firm was "observingthe situation. Dialogue is always to be welcomed. But it is tooearly to draw conclusions."
South Pars is a big draw for European oil and gas majors whoworked in Iran before the sanctions. Iran's oil minister BijanZanganeh says he has begun talks with potential investors.
France's Vallourec, which makes seamless steeltubing used in oil and shale gas drilling, said that if foreignfirms returned, "we will obviously be there to work with them".
WATCH AND WAIT?
Tockuss said German firms faced potential U.S. competitionand warned that EU sanctions might be more cumbersome to undothan U.S. embargos, allowing the Americans to act more quickly.
Should all sanctions be lifted, Iran could be worth perhaps5 billion euros of exports a year to Germany. They totalledalmost 4 billion euros in 2008, before sanctions took hold. Lastyear Iran bought just 2.5 billion euros' worth of German goods.
Omid Nouripour, a German-Iranian lawmaker for the Greens,advised careful preparation and lots of patience: "I would tellGerman business it is an exciting time; go to Iran, look, thenwait ... We need to see what happens in the next six months."