The Greek natural gas retail sector ended 2025 with market shares largely reflecting the previous year, despite intensifying competition across customer categories as suppliers sought to expand their presence. Consolidated annual data covering residential, commercial and industrial demand show that Zenith maintained its leading position with a 29.3% share, only slightly below the 29.5% recorded in 2024. Aerio Attikis followed with 26.9%, down from 29.2%, while Protergia strengthened its footprint, increasing its share to 18.5% from 16%. Heron also recorded a modest gain, rising to 11% from 10.6%. Public Power Corporation (PPC) moved into fifth place with 3.2%, surpassing DEPA, Enerwave and NRG. DEPA’s share declined to 3.1%, Enerwave remained stable at 3%, and NRG edged down to 2.5%.
Although overall market shares changed only marginally, industry sources point to more aggressive competition, particularly in the business supply segment, where suppliers revised pricing strategies and commercial terms to secure new contracts. This has resulted in a relatively stable market structure at headline level, while customer switching and competitive dynamics have become more pronounced beneath the surface.
Total gas consumption through distribution networks reached 13.05 TWh in 2025, marking an 11.25% year-on-year increase. In contrast, demand from heavy industry and compressed natural gas stations declined by 13.53%. Within the industrial and large commercial segment, Protergia emerged as the dominant supplier with a 36.9% share, followed by Heron at 19.4%, Zenith at 18.7% and Aerio Attikis at 12.1%. DEPA accounted for 7.1%, NRG captured 2.2%, Enerwave and EFA Energy each held 1.7%, and Volterra represented 0.2%.
In the residential segment, Zenith retained leadership but saw its share ease to 38.8% from 43.4%. Aerio Attikis followed with 25.6%, while Protergia and Heron expanded their presence to 8.8% and 8.4%, respectively. PPC rose to 8.3%, Enerwave remained at 4.7%, NRG slipped to 3%, and EFA Energy increased its share to 1.7%. Overall, the figures indicate that while the broader market structure remains stable, competitive pressures and segment-specific shifts are gradually reshaping Greece’s retail gas landscape.
