Bulgaria's gas transmission system operator Bulgartransgaz intends to invest 850.6 million levs ($506.5 million/434.9 million euro) in the country's gas infrastructure by 2027, it said.The largest portion of the investment is planned to be spent on reconstruction, rehabilitation and capital repair of long-term assets, Bulgartransgaz said in its 10-year business plan published on the website of the Energy and Water Regulatory Commission (EWRC).In terms of investments in new infrastructure, the major projects include the gas interconnectors with neighbouring Serbia, Greece and Turkey, as well as the development of a gas hub on the territory of Bulgaria.