Metlen Energy & Metals, the FTSE 100-listed Greek conglomerate formerly known as Mytilineos, has drawn scrutiny for its complex corporate structure. Executive chair Evangelos Mytilineos pivoted the family business toward international engineering projects, taking on significant debt. Central to this expansion is Nikos Papapetrou, head of Metlen's renewables development division since 2019, whose family company Egnatia is a key partner.

The relationship centers on Metka EGN, a 2015 joint venture combining Egnatia's solar development expertise with Metlen's engineering subsidiary. Metlen bought Egnatia's stake in 2020 for an initial €26mn plus an undisclosed earnout. Public filings reveal a valuation mismatch of approximately €80mn: EGN Projects, a Papapetrou family vehicle, valued the earnout at €105mn in 2021, while Metlen recorded just €24mn in liabilities.

Auditors issued qualified opinions on EGN Projects' accounts for 2021-2023, noting Metlen didn't provide information to validate the earnout and fell behind on payments. Papapetrou purchased €2mn of Metlen shares in May 2025 through Cyprus-registered Gioralex Holdings, which owns a third of EGN Holding, Egnatia's parent. Metlen maintains the 2019 transaction wasn't a related-party deal and complied with disclosure rules.