BUDAPEST, July 31 (Reuters) - Hungary has taken a key step towards importing small modular nuclear reactor technology by partnering with Poland's Synthos Green Energy, which holds the rights to GE Vernova Hitachi's technology in central Europe.

Hungarian nuclear energy development firm Hunatom signed a letter of intent with Synthos, which serves as project developer for building BWRX-300 reactors in the region.

"This agreement is about initiating the technological, infrastructural, financial, and legal preparatory work needed to bring this American nuclear technology to Hungary," Hungarian Foreign Minister Péter Szijjártó said late on Wednesday.

GE Vernova Hitachi is a joint venture between General Electric GE.N and Japanese conglomerate Hitachi 6501.T.

It was not immediately clear how many reactors Hungary wants. In 2023, Energy Minister Csaba Lantos said that Hungary will need to build at least one small modular reactor.

"The United States and Hungary are deepening our relationship across the board: in defense, in commerce, in space, and in energy," Robert Palladino, Chargé d’Affaires at the U.S. embassy in Hungary, said after the signing ceremony.

Hungary currently has a nuclear plant with four Soviet-made VVER reactor units, first brought online between 1982 and 1987.

In 2014, Hungary signed an agreement with Russian nuclear firm Rosatom worth 12.5 billion euros to build two 1.2 gigawatt reactors at Paks on top of the four existing reactors. However, the project, called Paks 2, has experienced long delays.

The project was awarded to Rosatom without a tender, and it is often cited as a sign of continued close ties between NATO and European Union member Hungary and Russia, despite the war in Ukraine - a connection that has unnerved Western allies.

(Reporting by Anita Komuves; Editing by Edwina Gibbs)

((KOMUVES.Anita@thomsonreuters.com;))