Traders book 46% of gas route to Ukraine

Greece, Bulgaria, Romania and Moldova have assembled a pipeline path to deliver liquefied natural gas to Ukraine. Traders are booking capacity along the route. But the public evidence proves the plumbing works, not that gas will reach Ukrainian storage this winter.

Booked pipes, missing contracts

LNG lands at Greek terminals, enters pipelines run by DESFA (Greece's gas grid operator), crosses into Bulgaria, transits Romania and reaches Ukraine via Moldova (European Commission). Each country runs its own grid, sets its own tariffs and answers to its own regulator. The European Commission's CESEC platform (a regional energy forum for central and south-eastern Europe) coordinates the effort, but it does not buy gas, set border tariffs or compel anyone to ship.

The strongest sign that this is more than a political map comes from the Greek-Bulgarian border at Sidirokastro. Traders booked 46% of available export capacity for gas years 2026/27 through 2029/30, with some reservations stretching to 2040/41 (Logos Press, Euro2day). Traders do not reserve multi-year cross-border pipeline space for decoration. On the supply side, DESFA handled 18.61 TWh of LNG in the first half of 2026, with the Alexandroupolis terminal more than tripling volumes year-on-year (Powergame).

Every hard datapoint stops before the Ukrainian border. Booked capacity shows traders want the option to move gas north. According to Model Diplomat, no public record shows who has contracted Ukraine-bound cargoes, at what price, or on which days molecules will flow. Romania's Transgaz reports 1.5 bcm/year of bidirectional capacity with Bulgaria, but no comparable figure exists for the Moldovan or Ukrainian exit (BVB/Transgaz).

Winter economics still favour the Russian-linked route

Timing squeezes the promise. Bulgaria's own capacity expansions at its Greek and Romanian borders are scheduled for late 2026, so this coming winter runs on existing pipes, not the planned build-out (Economic.bg). The larger corridor upgrade, from roughly 5 to 9.4 bcm/year, remains a financing commitment, not available capacity (Jurnalul).

Cost is the less visible constraint. The route became commercially thinkable only after operators bundled separate border crossings into single booking products with discounted tariffs, letting a trader reserve Greek-to-Romanian capacity in one transaction instead of negotiating three separate border fees (Economica). If those discounts lapse at any crossing, traders may keep reservations and skip actual shipments.

Bulgaria shows what that risk looks like. Bulgargaz used only about 23% of its contracted Turkish-route capacity in 2025, absorbing heavy costs for the unused rest (Novinite). Paying for pipes you do not fill is a warning, not a selling point.

The corridor's LNG also competes against TurkStream (which carries Russian gas through Turkey into south-east Europe), a route that avoids the liquefaction and regasification costs built into the new path. The Vertical Corridor wins only when buyers choose to pay a diversification premium. Greece, Bulgaria and Romania each collect different rewards for that bet: hub status, transit fees and future leverage once Romania's Neptun Deep gas field starts producing around 2027 (Economica). Hungary and Slovakia, outside the physical route, use winter energy anxiety to extract concessions on sanctions and supply, proof that cheaper Russian-linked alternatives still shape the politics (Topky).

Ukraine gets an option, not a guarantee. The route works, traders have reserved space and governments have declared their backing. What is missing is delivery evidence: named contracts, daily flow nominations, delivered prices. Until shippers and buyers speak as loudly as governments, the Vertical Gas Corridor can carry gas to Ukraine but has not shown it will.