Mazarine to Acquire Romania's Largest Offshore Gas Producer BSOG

Mazarine Energy has agreed to buy Black Sea Oil & Gas (BSOG), Romania's largest offshore natural gas producer, from Carlyle and the European Bank for Reconstruction and Development (EBRD). The price wasn't disclosed. That absence is the first thing a skeptic notes — but the asset itself is unambiguous: the Midia Gas Development (MGD), the first offshore production hub built in the Romanian Black Sea in more than three decades.

What changes hands?

BSOG operates MGD and holds a 70% operating interest in the project. The transaction also covers BSOG Holding Activity. It remains subject to customary regulatory approvals, so no completion date is on the table yet.

The asset footprint is concrete:

• The offshore Ana platform
• A 126 km subsea pipeline
• A new onshore gas treatment plant at Vadu

Carlyle backed BSOG in 2015, when it was still an exploration-stage business. The EBRD joined two years later. Under their ownership, BSOG led investment of more than $400 million in MGD on behalf of itself and its joint venture partners. That capital turned a explorer into the country's leading offshore producer — a rare private-equity offshore build that actually reached first gas.

How much gas is at stake?

Since first gas in June 2022, MGD has produced more than 100 million standard cubic feet per day. According to Romanian energy regulator ANRE, that output accounted for 11.8% of Romania's total natural gas production during the first half of 2026. One in roughly eight molecules of Romanian gas now flows through infrastructure that didn't exist four years ago.

Carlyle International Energy Partners co-head Bob Maguire framed the exit as proof of the model. "Over the past decade, BSOG has evolved into Romania's leading offshore gas producer and an important contributor to domestic energy supply," Maguire said. "The business demonstrates how patient, disciplined private capital can support complex offshore infrastructure, and we are pleased to transfer ownership to Mazarine, which shares our long-term commitment to Romania and its energy sector."

Read that carefully. "Transfer ownership" is seller language for a clean exit. What Mazarine inherits is a producing asset entering what the parties call its "next development phase" — a phrase left undefined in the announcement. No reserve figures, no drilling schedule, no capex guidance accompany it.

What does Mazarine get beyond the platform?

The operational side stays put. BSOG will continue to operate MGD after completion, preserving continuity.

The company is also pursuing carbon capture and storage (the capture of CO2 from operations and its permanent underground storage) opportunities in the Midia block. Through its subsidiary BSOG Energy, it holds early-stage positions in offshore wind and biomethane. All three lines are labeled opportunities and initiatives. None carries a sanctioned project, a budget or a timeline. Treat them as optionality, not cash flow.

For Mazarine, the deal deepens a Romanian footprint dating to 2017. The company, founded in 2013 by Edward van Kersbergen, also produces in Tunisia and entered the Dutch market in 2026 through a 50% stake in Wintershall Noordzee. This is a consolidator's move, not a first entry.

"Romania has been a core part of Mazarine Energy's business since 2017, and we are proud to build on that presence with BSOG," van Kersbergen said. "MGD is a major achievement for the country's energy security, and we are committed to carrying forward what the BSOG team has accomplished and to supporting Romania's energy supply for years to come."

Jefferies acted as financial adviser to Carlyle on the transaction. Mazarine's adviser, if any, wasn't named. Nor were the deal terms.

The takeaway: Romania's flagship offshore gas asset changes owners, the operator stays, and everything beyond the producing platform remains a promise. The watch items are regulatory approval, the disclosed price if it leaks, and whether Mazarine names the "next development phase" with actual wells and dates.