UPDATE 5-Iraq Kurdistan gas plan may cut Russian sway on EU

* Iraq Kurdistan gas could kickstart Nabucco project

* Development of Iraq Kurdistan gas fields to cost $8 bln

* OMV, MOL buy into Crescent, Dana Gas Kurdish venture

* Fields can pump over 3 bln cfd by 2014

(Adds analyst comment paras 8-9)

By Simon Webb

SHARJAH, United Arab Emirates, May 17 (Reuters) - A new bloc of European and Arab energy firms unveiled an $8 billion plan on Sunday to pump enough gas from Iraq's Kurdistan to kickstart the Nabucco pipeline project and reduce Europe's reliance on Russia.

Until now, the $10 billion Nabucco pipeline scheme had plenty of willing gas buyers in Europe, but little to sell. Europe imports a quarter of its gas from Russia and has backed Nabucco to help cut that dependence.

Gas from the semi-autonomous northern region of Iraq could help solve the Nabucco supply conundrum.

The United Arab Emirates' Crescent Petroleum and affiliate Dana Gas DANA.AD believe there is enough gas in the fields they operate in the Kurdistan region to supply the pipeline after meeting local demand in northern Iraq and Turkey.

Austria's OMV (OMVV.VI) and Hungary's MOL MOLB.BU, two of Nabucco's initial shareholders, have bought into the $8 billion scheme. They have joined forces with Crescent and Dana to take on the gas development plan, the companies first told Reuters in interviews and a joint statement on Sunday.

"We are confident that our assets in the region have the potential to produce over 3 billion cubic feet per day (cfd) by 2014," Badr Jafar, executive director for Crescent Petroleum, told Reuters.

Jafar declined to estimate how much would be available for the Nabucco project. An industry source told Reuters that around 1.5 billion cfd could go to the pipeline, sufficient to fill Nabucco's first phase.

"That quantity would certainly be enough to start Nabucco," said Jonathan Stern, director of gas research at the Oxford Institute for Energy Studies.

But questions remained over whether the size of the gas reserves quoted would be sufficient to supply those volumes of gas, over the speed at which they could be delivered to transit country Turkey and the position of Iraq's central government on the legality of the project, Stern added.

OMV was confident there was enough gas to meet domestic, Turkish and Nabucco demand.