The Transport Ministry of Bulgaria has extended the submission deadline for the tender to operate Sofia Airport, the country's primary international gateway, to 5 February.

The tender for the 35-year concession, valued at just under EUR3.5 billion (US$4.0 billion), was launched in July with responses due on 22 October. In September, the Commission responsible for overseeing the tender recommended a 30-day extension. The deadline was revised again in November to 29 January 2019.

The initial extension was due to questions from prospective bidders, which prompted the Ministry to amend the tender documents. However, the Ministry's notice disclosing this latest extension details that no other changes to the tender documentation have been made.

Located 10km from Sofia city centre, the airport handled around 6.5 million passengers in 2017, a 30.3% increase from the previous year. It has two terminals, with the selected concessionaire to deliver a third.