Having already built a new airport at Hyderabad, infrastructure major GMR Group, along with other consortium partners, today signed an agreement with the Turkish government to expand an airport at Istanbul, the commercial hub of the country.The GMR-led consortium will be developing facilities for trebling the passenger capacity of the Sabiha Gokcen International Airport (SGAI) at Istanbul with an investment of euro 250 million (about Rs 1,600 crore). According to a release issued by GMR today, in addition to making an initial investment to increase the capacity of the airport to 10 million passengers per annum in 30 months, the consortium will pay euro 1.92 billion concession fee spread over 20 years to the Turkish government.It will recover the money through various aviation and related activities, upgradation of the Sabiha Gocken Airport, named after a woman combat pilot and adopted daughter of the father of modern Turkey, Mustafa Kemal Ataturk."This project will increase the international exposure of the GMR Group...It will also serve as the ideal reference for entering into other European countries," GMR international division chief executive officer Ranjit Murugason said.(Reporting by Chandra Shekhar)