* EPEX to hold 25 pct stake in the new exchange
* Day ahead trading to start in Q3, intraday trading seen in 2015
* Future plans to link day ahead market with Hungary
KOPAONIK, Serbia, March 5 (Reuters) - Serbia has teamed up with European exchange EPEX Spot to launch a regional spot power bourse in the third quarter this year to introduce competition, develop reliable prices and security of supply in the region, its grid operator EMS said on Wednesday.
Paris-based EPEX will hold a 25 percent stake in the SEEPEX exchange, with EMS owning the remaining share, EMS general manager Nikola Petrovic said on the sidelines of an economic forum in the Serbian mountain resort of Kopaonik.
The Belgrade-based bourse would become fully operational in the first quarter of 2015, providing the Balkan country's efforts to liberalise its energy market with a view to joining the European Union go ahead as planned.
In the initial phase neighbouring Montenegro, Macedonia and Bosnia will join SEEPEX, Petrovic said. There are also plans to link the regional market with that of Hungary, which has already linked day ahead trading with the Czech Republic and Slovakia.
The bourse will first start trading day ahead power, while intraday trading will be introduced in 2015.
While many traders see the region as potentially lucrative, they cite barriers limiting market growth that include a lack of transparency, difficulties in getting trading licenses and the need to win numerous auctions to move around power.
Almost 10 percent of Serbia's electricity market was opened up in 2013 and 27 of the country's biggest industrial consumers were required to buy power on the open market.
Smaller commercial users have been able to buy on the free market since the start of 2014. Households may also follow suit in July, six months ahead of initial plans, officials have said.
Ljubljana-based BSP Southpool, run by international derivatives exchange Eurex and Slovenian power market operator Borzen, offers spot power trade for the Slovenian and Serbian markets but liquidity there has been poor.