Polish state-owned pipeline operator Gaz-System SA is able to offer virtual reverse flow services on the Yamal-Europe natural gas pipeline because potential contracts will likely be settled at a location on the German side of the Polish-German border, a person familiar with the matter said Thursday.

Making the point of settlement at Mallnow, an exit point of the pipeline located in the German town of Lebus, would enable potential German sellers of natural gas to sidestep a contract term with OAO Gazprom (GAZP.RS) that states Russian gas flowing through the pipe is the property of the Russian state-owned gas giant, not the party that purchased the gas, until it leaves Polish territory, the person told Dow Jones Newswires.

"Settlement of the virtual reverse will take place at the Mallnow point, outside
Poland 's borders, as well as at exit points of the Yamal pipeline into the Polish system at Wloclawek and/or Lwowek," Gaz-System said Thursday.

Gazprom wasn't immediately available for comment.

Under this virtual reverse flow arrangement, the physical gas would be released within
Poland , the person said. The exit points Gaz-System is offering at Wloclawek and Lwowek are in central and western Poland , respectively.

In early September,
Poland took steps to liberalize its natural gas market when the country's energy regulator URE approved a procedure enabling buyers of Russian Yamal-delivered gas in Germany to sell it back to buyers in Poland . A month later Gaz-System said total requests for the service exceeded the pipeline's reverse flow capacity, which allows for delivery of about 2.3 billion cubic meters a year.

Skeptics who doubt whether the reverse flow service will actually be used by Polish customers to buy gas from sellers in
Germany have a point, the person said. Potentially, Gazprom could buy up the entire 2.3 billion cubic meters spare capacity, effectively paying Gaz-System for a service it wouldn't use, as the gas wouldn't flow through the pipeline to a buyer.

"However, once it happens and turns out to be real, the trend will be unstoppable," the person said. "Other customers in
Poland and sellers in Germany will then also clamor for the service, once they see others using it."