Hungary's state-owned utility company MVM Zrt. has brought a 50% stake in the implementing company for the Hungarian stretch of the South Stream natural gas pipeline from state-owned development bank MFB Zrt., MVM said Friday.

Hungary's government initiated the transfer of the stake in Deli Aramlat Zrt. at the start of the year, a move seen as part of scheme to broaden the energy portfolio of electricity firm MVM.

"Technical, legal, and business experts are in negotiations with the implementation company's other owner, Russian energy company OAO Gazprom (SIBN.RS) over the Hungarian stretch of the project," MVM said in a statement issued after the company's general assembly Friday.

The project company is set to construct the Hungarian stretch of the South Stream gas pipeline, which will deliver 63 billion cubic meters of gas annually from the Black Sea to south and central Europe from 2015.

Write to Marton Eder at marton.eder@dowjones.com