Herbert Smith Freehills Kramer advises Carlyle on the sale of Black Sea Oil & Gas

Leading global law firm Herbert Smith Freehills Kramer has advised Carlyle on the sale of Romania’s largest offshore natural gas producer, Black Sea Oil & Gas (“BSOG“), to Mazarine Energy B.V. The sale is being undertaken by Carlyle and its co-owner, the European Bank for Reconstruction and Development.

Carlyle is a global investment firm with $479 billion of assets under management as of September 30, 2026. Under Carlyle’s ownership, BSOG, as operator, has led, on behalf of itself and its joint venture partners, the investment of more than $400 million in the Midia Gas Development project, the first offshore hydrocarbon production hub in the Romanian Black Sea in more than 30 years. The project included the development of the offshore Ana platform, a 126-kilometre subsea pipeline and the new onshore gas treatment plant at Vadu. Since coming online in June 2022, BSOG has supplied approximately 12% of Romania’s domestic gas demand, contributing to the country’s energy security during a critical period for European energy markets.

The Herbert Smith Freehills Kramer team was led by Corporate Energy partner Laura Hulett, supported by partners John Taylor, Will Nevin and William Arrenberg, senior associates Valerie Lowe and Tom Watkins, and associates Daniel Clarke and Darius White. The wider Herbert Smith Freehills Kramer team included André Pretorius, James Tryfonos, Will Beynon and Max Kaufman.

Partner Laura Hulett said: “We are delighted to have advised Carlyle on this transaction, building on our long-standing relationship with the Carlyle International Energy Partners team and Carlyle’s portfolio company, BSOG since Carlyle’s initial investment in BSOG in 2015. This transaction showcases our ability to draw on our strengths across corporate energy and private capital.”

The transaction is subject to customary regulatory approvals.