Bulgaria's gas transmission system operator Bulgartransgaz said that it has opened a tender for a 48 million levs ($28.4 million/24.5 million euro) framework agreement for carrying out archaelogical studies in relation to the development of the local gas infrastructure. The term of the framework agreement will be four years, Bulgartransgaz said in a tender notice. The deadline for submitting offers is November 15.Bids will be ranked based on price and technical criteria.(1 euro = 1.95583 levs)