Baku, January 3, AZERTAC Türkiye and Bulgaria on Tuesday signed an agreement for the transmission of up to 1.5 billion cubic meters of natural gas a year, according to Anadolu Agency. The new deal covers a 13-year period, said Turkish Energy and Natural Resources Minister Fatih Donmez visiting the capital Sofia, hosted by his Bulgarian counterpart Rossen Hristov.Donmez added that such cooperation would contribute greatly to the natural gas supply security of Europe, along with Bulgaria.The gas deal was signed between the two countries by the general managers of the Turkish Petroleum Pipeline Company (BOTAS) and Bulgargaz.The deal comes a month after both country leaders and energy ministers met in Istanbul."We are pleased that the topics discussed in Istanbul have turned into concrete steps in Sofia today, less than a month after our last meeting," Donmez said.