The Union government may float tenders for greenfield airport projects at Mopa in Goa and Navi Mumbai in Maharashtra by the end of this year, says a joint report by the Centre for Asia Pacific Aviation (CAPA) and airline IT services provider SITA.    The joint think tank report said that approximately $10 billion was invested in airport modernisation between 2015 and 2012. In early 2013, new airport terminals were completed at Chennai and Kolkata airports, while Mumbai is expected to open terminus two to domestic traffic in late 2013.    The document was released during the Aviation ICT Forum 2013 in Panaji, Goa on September 26.  The document state that by the year-end, new terminals will be inaugurated at all six metro airports representing a significant milestone in the airport modernisation programme.    The Union government wanted to encourage development of 50 greenfield low-cost airports primarily in Andhra Pradesh, Karnataka, Rajasthan and Uttar Pradesh.