Carlyle and the EBRD agree to sell Romania's Black Sea Oil & Gas to Mazarine Energy
The producer behind the Midia Gas Development has supplied about 12% of Romania's domestic gas demand since 2022. The deal still needs regulatory approval.
Carlyle and the European Bank for Reconstruction and Development (EBRD) announced on Thursday 29 October that they have agreed to sell Black Sea Oil & Gas (BSOG), which Carlyle describes as Romania's largest offshore natural gas producer, to Mazarine Energy B.V. The deal is subject to customary regulatory approvals.
The price was not disclosed, Reuters reported. The EBRD owns 10% of BSOG. Carlyle founded the company in 2015 and brought in the EBRD as a minority investor two years later.
The asset
BSOG is the 70% owner and operator of the Midia Gas Development (MGD), the first offshore hydrocarbon production hub in the Romanian Black Sea in more than 30 years, according to the Carlyle release. BSOG has led the investment of more than $400 million in the project on behalf of itself and its joint venture partners. MGD includes the offshore Ana platform, a 126-kilometre subsea pipeline and a new onshore gas treatment plant at Vadu.
Since production began in June 2022, BSOG has supplied about 12% of Romania's domestic gas demand, the release says. Reuters put the figure at about 10% of the country's gas needs. The project came online months after Russia's full-scale invasion of Ukraine, at a critical moment for European energy markets.
BSOG will remain the operator of MGD after the sale. The company says it is also pursuing carbon capture and storage using its existing infrastructure, offshore wind along its energy corridor, and biomethane plants through its subsidiary BSOG Energy.
The buyer
Mazarine Energy is an independent oil and gas company founded in 2013 by Edward van Kersbergen, according to the release. It produces in Tunisia and Romania and entered the Dutch market in 2026 by acquiring a 50% stake in Wintershall Noordzee B.V. Reuters described Mazarine as a former Carlyle portfolio company.
"Romania has been a core part of Mazarine's business since 2017, and we are proud to build on that presence with BSOG," van Kersbergen said in the release.
What the sellers said
"When Carlyle invested in BSOG in 2015, the company was an exploration-stage business," said Bob Maguire, Co-Head of Carlyle International Energy Partners. "The business demonstrates how patient, disciplined private capital can support complex offshore infrastructure."
His fellow co-head, Guido Funes Nova, pointed to significant remaining resources, carbon capture and storage potential in the Midia block and a pipeline of biomethane projects. Victoria Zinchuk, the EBRD's Regional Head of Romania, Bulgaria and Greece, said the company had brought an important offshore resource into production and helped diversify Romania's energy supply.
Jefferies advised Carlyle on the transaction. BSOG also published the announcement on its website, and Bucharest outlet The Diplomat reported the agreement.
Romania's gas position
Unlike many European states, Romania did not rely on Russian gas and produces most of its needs domestically through OMV Petrom, state-owned Romgaz and BSOG, Reuters noted. OMV Petrom and Romgaz are building the much larger Neptun Deep project in the Black Sea, which they and the government expect to start producing in 2027. They expect it to make Romania the largest gas producer in the European Union and a net exporter.
The region also carries security risks. Reuters reported that Romania has repeatedly recorded Russian drone incursions into its airspace since 2022, and mines have been found floating in the Black Sea along key trade and energy routes.
What it means for founders and investors
For private equity and infrastructure investors, BSOG is a full-cycle example: Carlyle backed an exploration-stage company in 2015, brought in a development bank as co-investor, built the asset and is now selling a producing business to a specialist operator. Exit timelines of a decade or more are typical for this kind of energy asset. Another private equity exit in European energy infrastructure this week was Triton's sale of Trench Group to GE Vernova.
The EBRD's role is also worth noting. Development banks can make large, risky projects in emerging European markets easier to finance by taking minority stakes alongside private capital.
For energy-tech founders, the mentions of carbon capture, offshore wind and biomethane show that producers are looking for new uses for existing pipelines, platforms and land. Startups working on monitoring, emissions measurement, CCS engineering or biomethane can find customers among mid-sized operators like Mazarine, not only among majors. Investors in this space include funds such as AP Ventures, which just closed a $300 million fund for industrial and energy technology.
What to watch
Watch for regulatory approval and the closing date, any disclosure of the price, and whether Mazarine moves ahead with the carbon capture and biomethane projects BSOG has been preparing.
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