Prime Minister: EU Gas Ruling Against Bulgaria is a Heavy Blow

SOFIA, June 29 (Reuters) - EU antitrust regulators have told Bulgaria it should sell its state-owned gas network operator Bulgartransgaz or face fines of up to $333.27 million (300 million euros), Bulgarian Prime Minister Boiko Borisov said on Wednesday.

Speaking to reporters in Brussels, Borisov said such a sanction would be unacceptable to Bulgaria.

Last year the EU executive commission charged state-owned Bulgarian Energy Holding, the owner of Bulgartransgaz, with breaching EU antitrust rules by hindering competitors' access to key gas infrastructure in Bulgaria.

"When (EU Competition) Commissioner Margrethe Vestager comes and says that you need to sell Bulgartransgaz, for us this is a heavy political blow ... Otherwise an infringement procedure of up to 300 million euros follows," Borisov said in an audio file, sent by the government press office.

($1 = 0.9002 euros) (Reporting by Tsvetelia Tsolova, editing by Louise Heavens)