* Part of regional expansion plan
* Four countries seen as a priority
SARAJEVO, Sept 2 (Reuters) - Serbian oil firm NIS, majority owned by Russia's Gazprom Neft , plans to set up subsidiaries in Bosnia, Bulgaria, Hungary and Romania as part of its regional expansion strategy, the company said on Friday.
Under a 2009 energy pact between Russia and Serbia, Gazprom Neft, the oil arm of export monopoly Gazprom , paid 400 million euro ($574 million) for a 51 percent stake in NIS and raised its holding to 56.15 percent in March for another 40.3 million euros.
In August, NIS reported a net profit of 21.4 billion dinars ($304 million) in the first half of 2011 after a 9.6 billion loss in the same period of 2010. It had said it aimed to triple crude output and almost double sales by 2020 to become the regional market leader.
"The registration of subsidiaries in Romania, Bulgaria, Hungary and Bosnia is a NIS' step towards the realisation of a strategy to develop business in the Balkan region and initial phase in actively entering these markets," NIS said in a statement to Reuters.
In May, NIS and Canada-based East West Petroleum Corporation (EWP) signed a deal to develop four oil and gas exploration blocks in Romania.
NIS had earlier said it planned to invest $740 million to complete the overhaul of its two rafineries in 2012, which would enable it to harmonise the quality standard of the fuels it produces with those in the European Union. (Reporting by Daria Sito-Sucic; Editing by Michael Kahn) ($1=.6969 Euro) (1$=70.4 dinars)