UPDATE 1-Limited impact seen if Iran's natgas exports cut-US EIA

* Congress considering broader sanctions on Iran

* Turkey takes 90 percent of Iran's natgas exports

* Natural gas markets regional, not global, unlike oil

(Adds details from report, analyst comment)

By Roberta Rampton and Timothy Gardner

WASHINGTON, Oct 9 (Reuters) - A reduction in natural gasexports from Iran would not have much impact on world energymarkets, but could hurt Turkey and part of Azerbaijan, accordingto a U.S. report due to be released on Tuesday.

The report is designed to be used by the U.S. administrationas it considers whether to broaden sanctions on Iran over itsdisputed nuclear program to include sales of natural gas.

"The potential global impacts of restricting Iranian gasexports are limited," the U.S. Energy Information Administrationreport said.

The report, a copy of which was obtained by Reuters ahead ofits publication, was required by the latest U.S. sanctions lawagainst Iran signed in August.

The United States and other Western nations have targetedIran's energy sector for sanctions as an effort to cut offrevenues it believes Iran is using to build nuclear weapons.Tehran has insisted its program is for civilian purposes.

The European Union is poised to ban imports of Iranian gas,a measure it may formally adopt at a meeting of foreignministers on Oct. 15.

"The (EIA) report gives cover for the administration tobroaden sanctions to cover natural gas exports," said MarkDubowitz, the head of the Foundation for Defense of Democracies,an advocate for stronger sanctions on Iran.

Iran has large reserves of natural gas, but its currentexports go mainly to Turkey, which buys more than 90 percent ofthe output under long term contracts. Armenia and Azerbaijanpurchase 6 percent and 3 percent, respectively.

"Clearly, Turkey would be placed in a very difficultposition in the event that it is unable to continue importingIranian natural gas," the EIA said.

A prolonged period without access to Iran's natural gascould "have a major disruptive effect" on Turkish industry, homeheating and power generation, the report said.

Congress is also considering tweaks to a U.S. sanctions lawthat could blacklist a broader range of Iran's energy sector.

(Editing by Tim Dobbyn and Andre Grenon)


@robertarampton)(+202 898 8390))