Bulgargaz has asked the energy regulator, the EWRC, to raise the price of natural gas by just over 14% for December.
If the regulator agrees, a megawatt hour of gas will cost €66.83, not including fees and levies.
The price covers Azerbaijani gas under the long-term contract, liquefied natural gas imported from Turkey and Greece, and gas taken from the Chiren storage facility. Azerbaijani gas makes up almost a third of consumption.
It also includes a fee for the Turkish company Botas on the gas planned for import from Turkey. Bulgargaz says the fee is reduced.
The proposal will be discussed in public before the EWRC makes its final decision.