Gas in South-East Europe is not just a commodity. It is infrastructure, geopolitics, finance, and strategic vulnerability wrapped together. Unlike electricity, which is inherently domestic to its grids even when cross-border trade is high, gas is structurally external in SEE. These markets depend on who can bring molecules into the region, who controls the pipelines, who finances the storage, who negotiates long-term contracts, and who has the flexibility to arbitrage between oil-indexed legacy deals and market-based pricing hubs. To ask who shapes gas liquidity, cross-border flows and price discovery in SEE is therefore to examine a complex architecture that stretches from Russia and Turkey to Greece, Italy, Austria and increasingly LNG-linked supply chains.
The most important starting point is geography. Hungary, Romania, Bulgaria, Serbia, Croatia and Bosnia do not exist as isolated gas islands. They are physically tied into European, Mediterranean and Eurasian supply systems. Two core supply vectors dominate: the Southern Gas Corridor–Turkey axis and the Central European corridor via Austria, historically shaped by Gazprom. Around these two axes, new LNG sources, regional interconnectors, storage capacity and regulatory frameworks compete to define who truly has power in the system.
Hungary remains the strategic benchmark in regional gas trading much like it does in electricity. Hungary’s gas system is anchored by FGSZ as the TSO, substantial cross-border interconnections and one of the largest underground gas storage capacities in the region. Budapest also historically anchored Russian contractual supply arrangements that many neighbouring countries indirectly leaned on. Hungarian gas pricing has traditionally mirrored Central European pricing dynamics, closely linked to Austria’s Baumgarten hub and European benchmark movements. This infrastructural and financial depth allowed Hungary to influence regional flows simply by virtue of being able to absorb and redirect volume. Even as European diversification reshapes supply dynamics, Hungary still embodies gas gravity: it is central not only geographically but commercially, because traders, utilities and regional governments view Hungarian price behaviour as an essential reference point for SEE.
Romania, unlike many of its neighbours, is not structurally dependent on imported gas in the same way. Domestic production and the long-anticipated Black Sea offshore potential have given Romania a different strategic posture. Romania matters because it represents potential independence in a region otherwise defined by dependency. Romania’s gas ecosystem—producers, grid operator Transgaz, storage and market functionality—creates localized liquidity supported by domestic supply, but its importance for the broader region lies ahead. As offshore production matures and as Romania upgrades its interconnection infrastructure, it becomes one of the few SEE actors capable of fundamentally shifting external reliance patterns. The Romanian system is therefore less about daily price discovery today than about strategic promise: the possibility that SEE could one day balance Russian, Turkish and LNG exposures with credible regional supply.
Bulgaria sits at the heart of one of the most politically significant gas crossings in Europe: the entry from Turkey and the now-institutionalised influence of Turkish gas system control. For years Bulgaria depended overwhelmingly on Russian pipeline gas. That has changed, structurally rather than symbolically. Greece’s LNG terminals, the IGB interconnector between Greece and Bulgaria, and the entrance of Azerbaijani gas into the Bulgarian system have transformed Sofia’s place in the regional gas trade. Bulgaria has become the bridge market between Greek LNG, Azeri pipeline supply, Turkish brokerage realities, Balkan demand and Central European transmission aspirations. It is also a corridor where political positioning, regulatory power and trading competition converge. Price discovery in Bulgaria therefore combines local system realities with broader Mediterranean and TurkStream-driven dynamics. Traders see Bulgaria as one of the key volatility points in SEE because regulatory intervention, regional geopolitics and infrastructure events can move prices sharply.
Serbia’s role in gas mirrors its role in electricity: it is physically central, structurally dependent and strategically important. Serbia’s gas system centres on Srbijagas, interconnections with Hungary and Bulgaria, and a strong reliance on pipeline supply historically linked to Russia. With the route through Turkey becoming dominant following the evolution of TurkStream/South Stream replacements, Serbia finds itself plugged tightly into the southern corridor. What Serbia shapes is not the price baseline but rather the regional balancing requirement. When Serbia must secure volumes, the regional system tightens. When pipeline stability or price disputes emerge, Serbia becomes a focal pressure point. Traders with portfolio reach into Hungary, Bulgaria, Greece and LNG chains view Serbian gas reality not as isolated, but as a critical node that regularly needs balancing and financial cover in volatile periods. Serbia also indirectly influences Bosnia and Montenegro, both of which rely on Serbian system dynamics to some extent for their energy security posture.
Croatia, however, fundamentally altered regional gas power balance by doing something most Balkan countries did not: it built LNG. The Krk LNG terminal transformed Croatia from a structurally vulnerable state into a strategic energy entry point for Central and South-East Europe. Croatia today is not only balancing its own demand; it is supplying neighbouring countries, shaping cross-border flows, and attracting the interest of global LNG suppliers, European trading houses and regional buyers. Krk LNG symbolically breaks the monopoly psychology of pipeline dependency. Commercially, it gives Croatia leverage: whoever controls LNG import flexibility controls winter security narratives, pricing stability and strategic decision-making leverage during shocks. Coupled with connections into Hungary and Slovenia and the ability to influence Bosnian and Serbian dynamics indirectly, Croatia has moved from being a recipient of gas realities to being a source of alternatives in the regional price discovery structure.
Bosnia and Herzegovina, in contrast, illustrates vulnerability. With minimal infrastructure diversification, strong dependency on single-route supply and limited storage capacity, Bosnia is gas-weak. It does not create liquidity; it absorbs conditions created elsewhere. Yet Bosnia matters for regional flows because its fragility means that supply disruption, price surges or infrastructure tension can turn into political pressure faster than in more diversified systems. As energy becomes increasingly political in SEE, Bosnia’s weak diversification makes it a barometer for how far regional supply resilience truly goes. Its lack of leverage paradoxically contributes to shaping the regional system because it is precisely the type of market that large trading houses, pipeline owners and regional infrastructure planners must consider when they design supply strategies.
At this point, one must step away from countries and look at who actually moves gas. Unlike electricity, where dozens of traders actively shape day-ahead and intraday liquidity, gas in SEE remains significantly influenced by state companies, infrastructure operators, long-term contract holders and a relatively smaller circle of powerful energy trading companies. Gas control in SEE is institutional, infrastructural and contractual before it is financial. Transmission system operators—FGSZ in Hungary, Transgaz in Romania, Bulgartransgaz in Bulgaria, Srbijagas, Plinacro in Croatia—exercise structural authority simply by controlling capacity, interconnections and system balancing functions. They do not trade in the commercial sense, but they determine physical architecture, which is power in itself.
Then come the long-term supply controllers. Historically, Gazprom dominated this role. Even as European policy gradually diversified supply and LNG reshaped price flexibility, Gazprom’s legacy contracts, its pricing approach, and its geopolitical signalling continue to influence SEE markets psychologically and practically. However, the picture has diversified. Azerbaijani gas through TAP and TANAP, Greek LNG increasingly flowing into Bulgaria and potentially upward, Croatian LNG feeding inland markets, and the ability of European trading companies to arbitrage global LNG cargoes into SEE have diluted monopolistic dominance. This does not yet mean SEE gas is fully free; it means control is now shared across several arms rather than held in one fist.
The true liquidity engines in SEE gas today are a combination of large multinational energy companies, European trading houses and regionally anchored commercial players who can book capacity, negotiate supply, manage storage and arbitrage between hubs like TTF, Austrian VTP and emerging SEE marketplace dynamics. Companies with strong positions in electricity trading—Axpo, MET, GEN-I, large European utility trading arms, oil and commodity majors like Shell or TotalEnergies in LNG—naturally extend influence into gas. These players are not everywhere with equal visibility, but their strategic approach to SEE gas is similar to electricity: treat the region as a portfolio space rather than a set of isolated countries.
Storage is another overlooked source of real power. Gas storage in Hungary, Romania and to a degree Croatia gives these countries a tool that the electricity sector does not have: the ability to time-shift geopolitical events. Whoever has storage controls fear and time. In crisis periods, storage cushions panic, controls price surges and gives traders arbitrage and security leverage. In gas markets, winter is not just a season; it is a pressure multiplier. SEE countries with storage capacity can ride volatility and negotiate better. Countries without storage are forced into short-term price vulnerability and structural negotiating weakness. That reality shapes liquidity because storage-rich systems attract trading volume and confidence, while storage-poor systems attract emergency procurement and political anxiety.
Price discovery in SEE gas is not born locally; it is imported. European benchmark hubs, LNG price dynamics, geopolitical risk premiums and oil product indices still heavily influence SEE pricing. Hungary’s system references European hubs. Romania tracks a hybrid model of domestic dynamics and continental market movements. Bulgaria’s prices reflect regional arbitrage possibilities and policy decisions. Serbia’s pricing has historically followed contractual structure rather than full market liberalisation, while Croatia now integrates LNG-driven flexibility with regional price realities. This layered price inheritance means SEE is not yet a price-making gas region; it is a price-translating region.
And yet, within this translation process, control emerges. Control lies with those who can offer alternatives. Croatia’s LNG is control. Azerbaijan’s capacity into Bulgaria and beyond is control. Greek terminals feeding northwards are control. Hungarian storage is control. Romanian production potential is future control. Turkish energy diplomacy exerts control. Meanwhile, European Commission policy, infrastructure funding, regulatory pressure and liberalisation enforcement shape the boundaries of how commercial actors play inside this space. Those who can combine infrastructure, contracts, liquidity access and geopolitical reading ability are the ones who truly decide regional gas outcomes.
Large European energy trading firms, fundamentally, exercise day-to-day influence by being able to secure supply, balance portfolios and financially smooth out shocks. State companies exercise sovereign influence by negotiating long-term strategies and cross-border infrastructure decisions. Transmission operators exercise operational influence by deciding how capacity is allocated, how systems are managed and how projects are prioritised. LNG suppliers exercise opportunistic influence when global market tightness creates leverage windows. Russia, Turkey, Azerbaijan and broader European policy each exert structural influence.
In the years ahead, SEE gas control will shift even further from single-supplier dominance toward a competitive balance between LNG, southern corridor pipeline gas, residual Russian contracts, Romanian production and emerging hub dynamics. Liquidity will increasingly originate from Greece-Bulgaria-Romania-Hungary axes. Cross-border flows will be determined less by legacy dependency and more by price competition and infrastructure efficiency. Price discovery will remain externally anchored but will gradually internalise as SEE consumption markets mature, diversify and digitalise.
So who truly shapes SEE gas markets? It is not any one company, one pipeline, or one policy institution. It is an interplay. Hungary shapes gravity through storage, position and historical depth. Romania shapes strategic independence through production. Bulgaria shapes volatility and corridor politics. Croatia shapes diversification through LNG. Serbia shapes necessity through central dependency. Bosnia shapes vulnerability awareness. Traders, state actors, LNG players and TSOs collectively shape liquidity and pricing reality.
Gas in SEE is therefore not controlled—it is balanced. And the real power belongs to those who know how to balance it.