THESSALONIKI – Construction on the Metro system in Greece’s second-largest city, Thessaloniki, is expected to be finished by the autumn of 2024 – some 18 years after it began – although an extension to the suburb of Kalamaria will take until 2025.

That was the new timetable, pushing back the opening by almost a year, with a contract signing with a private operator celebrating the work at a ceremony attended by Prime Minister Kyriakos Mitsotakis.

This being Greece, there could be more delays. “We can’t say precisely when, because we need to wait for the company and its systems to get certified,” said Deputy Infrastructure Minister Nikos Tachiaos.

The Thessaloniki metro is Greece’s first public-private partnership, with the French-Italian Thema consortium of ΑΤΜ and EGIS, a 12-year contract with a budget of 292 million euros ($306.9 million.)

“We made a bold decision to use private expertise, the best at a European level, in order to ensure the project’s smooth and safe operation,” Mitsotakis said at the signing, although the total cost of the project isn’t known yet.

The system was supposed to open in 2012. Elliniko Metro, the public company responsible for Athens’ and Thessaloniki’s metro systems put the estimated cost at 2.086 billion euros ($2.19 billion.)

That’s based on 1.5 billion euros ($1.58 billion) for the main line and 586 million euros ($615.9 million) for the Kalamaria extension – but seen continuing to rise until the work is finally done.

Mitsotakis said the 250-million euro ($262.76 million) contract signing was especially important because “recent events have brought back to mind the sins of the past, when we did not know who was responsible for maintaining important infrastructure paid for by Greek taxpayers.”

It wasn’t said if that was a reference to the rusting of the 265 million euro ($278.52 million) roof of the Athens Olympic Stadium that was allowed to deteriorate for 19 years, leading to it being shut down.

He was given a tour of the archaeological site lying beneath the Agia Sofia station, where the ceremony took place and where, as at the Venizelos Street station, revealed archaeological finds from the dig.