The construction sites of Rome's troubled Metro C reopened on 10 September following a late-night agreement reached on 9 September between Roma Metropolitana, the Metro C consortium and the city.

Construction work had ceased on the 21.5-km metro project on 9 August following a dispute over the city's alleged non-payment of over €250 million dating back to 2011 during the administration of former mayor Gianni Alemanno.

The city had been given a deadline of midnight on 10 September to reach an agreement otherwise the project's workers would take to the streets. A statement released by Roma Metropolitana said "As requested by the funding bodies the work time schedule was also redefined in order to allow the opening to the public in summer 2014 for the Pantono-Lodi stretch and winter 2015 for the S. Giovanni station."

The news was welcomed by Rome mayor Ignazio Marino who has called for transparency in relation to the project's funding, including contested extra costs, since being elected in June. Marino tweeted "the agreement on the Metro C is good news for Romans. Transparency in the management of public funds is always the way forward."

However deputies from the Sinistra Ecologia e Libertà (SEL) party have requested that transport minister Maurizio Lupi reveal the full amount of public costs incurred to date for the design and construction of the Metro C, in particular the funds still required to complete the project.

Construction work on the central section of the Metro C between S. Giovanni and the Colosseum began in the spring. The seven-year project will cost €792 million and will cover a three-km stretch including two metro stops: Amba Aradam-Ipponio and Fori Imperiali-Colosseo.

Both stops are key to the success of the underground line which will eventually be linked to Metro A in S. Giovanni and Metro B at the Colosseum. Last year the audit court president Luigi Giampaolino said that the Metro C seemed set to become “the most expensive and slowest public works project in Europe and the world.”

Since work on the new line began in 1990, the project's costs have spiralled from €1.9 to over €5 billion, and the route is still nowhere near completion. The crucial section across the historic centre from Colosseum to S. Pietro, much talked about when work began, is now hardly ever mentioned. Difficulties below the surface, with crucial archaeological remains along the route, are making planning too difficult or too expensive to contemplate.