Carlyle and the European Bank for Reconstruction and Development (EBRD) have agreed to sell Black Sea Oil & Gas (BSOG), Romania's largest offshore gas producer, to Mazarine Energy. The price was not disclosed, and the transaction remains subject to regulatory approval. BSOG will remain operator of the Midia Gas Development, which has supplied around 12% of Romania's domestic gas demand since coming online in June 2022.
Carlyle's energy fund, Carlyle International Energy Partners (CIEP), took a majority stake in Mazarine in 2016 and sold it to founder Edward van Kersbergen in a buyout completed in early 2025. Less than two years later, van Kersbergen is taking on Carlyle's Romanian gas business as well. "When Carlyle invested in BSOG in 2015, the company was an exploration-stage business," said Bob Maguire, co-head of CIEP.
Carlyle entered in 2015 by buying the Romanian business of Sterling Resources for a headline $42.5m, acquiring operated stakes in the Midia and Pelican blocks. The EBRD joined as a minority shareholder in 2017, taking what Reuters describes as a 10% stake. Romania introduced supplemental offshore taxes in 2018, and BSOG and its partners approved the $400m project in February 2019 on the assumption those levies would be removed. Few sponsors attach that kind of caveat to an investment decision, underscoring the political risk Carlyle carried.
Operationally, the bet paid off. BSOG installed the Ana platform about 120km offshore in 2021, and first gas flowed on 15 June 2022, at a critical moment for European energy markets. As operator and 70% owner, BSOG has led more than $400m of investment. Whether the sale delivers a financial return remains unclear, since no price was disclosed. For Mazarine, the acquisition doubles down on Romania, though expanding offshore will be harder, as Romania last tendered offshore exploration blocks in 2010.
Source: PE Insights · Summarized by HeadlinesBriefing