The government announced the criteria for the concession of Sofia Airport

At least EUR 600m of investments over 35 year period would be demanded from candidates in the concession procedure of Sofia Airport. Furthermore, the chosen company would have to pay to the state at least BGN 15m, but no more than 10% of annual revenue generated by the airport and construct a third transportation terminal by the end of the 10th year of the contract as part of the required investments. A candidate must have at least EUR 200m net asset value over the last 3 years, operate at least one other airport transporting 10m passengers annually and to have an experience in infrastructure investments of at least EUR 400m in size. The score of the bids will be determined based 55% on the offered concessional payment and 45% on the technical proposal, including business plan, financing, forecast, CAPEX schedule etc.