SOFIA (Reuters) - Bulgaria has agreed to buy U.S. natural gas for the first time, signing a deal for a delivery in the second quarter and another in the third, the Bulgarian energy minister said on Friday.

Dutch-registered trader Kolmar NL will deliver a 90 million cubic meter (mcm) cargo of liquefied natural gas (LNG) and a second of 50 mcm.

“The ship carrying LNG from the United States has arrived at the Greek Revithoussa LNG terminal,” Energy Minister Temenuzhka Petkova said. “This is yet another step towards liberalization of the gas market and a clear sign of diversification.”

The first LNG shipment is from U.S. producer Cheniere and the second one is from the U.S. unit of BP, she said.

Bulgaria signed a contract in April with Greek DEPA for another small gas shipment, part of efforts to reduce an almost complete dependence on supplies from Russia’s Gazprom. Bulgaria said it would diversify after a 2009 row with Moscow disrupted winter supplies.

The new contracts covered about 10 percent of Bulgaria’s gas needs and priced at a level to gas prices in Bulgaria to be cut in the third quarter, state gas wholesaler Bulgargaz said.

Bulgaria plans to launch its own natural gas trading bourse in October and said Kolmar NL had expressed interest to offer about 500 mcm of LNG a year for the bourse over five years, Petkova said.

Bulgaria is set to receive mainly Azeri gas via a 182 km (113 mile) interconnector link with Greece that is expected to be ready by the end of 2020, with an initial annual capacity of 3 billion cubic metres.