A contract worth up to €550 million to oversee the construction of Dublin’s MetroLink rail line has been awarded to engineering and consultancy consortium Jacobs and Aecom.

The 12-year “programme delivery partner” contract is the largest awarded to date in the development of the 19km rail line from Swords in north Co Dublin to Charlemont on the south side, serving Dublin Airport and the city centre.

The announcement comes in advance of a decision by the Government, expected next week, on whether to allow the State’s MetroLink developer Transport Infrastructure Ireland (TII) to seek bids to build the line, based on new cost estimates completed earlier this year.

The estimates, submitted as part of the MetroLink business case, have not yet been published but are expected to range from about €14 billion to €17.5 billion. The last published estimates, drawn up in advance of the planning application for the line four years ago, calculated €9.5 billion as the midpoint of a “credible” cost range of between €7.16 billion and €12.25 billion.

Jacobs and Aecom will be tasked with “ensuring that all aspects of the MetroLink project are delivered within a defined budget, required time frame, and to the highest standards of safety and quality”, said TII.

Transport Infrastructure Ireland chief executive Lorcan O’Connor said the appointment “marks a critical transition for MetroLink as we move from planning into full-scale delivery preparation”. The multiyear contract ensured “maximum transparency and value for public money,” he said.

TII expects it will have spent almost €750 million on MetroLink by the end of this year, before construction begins on the line.

The expenditure includes several large property deals. UK property group Hammerson sold more than one hectare (2.5 acres) of land on O’Connell Street to TII in July as part of a €80.7 million divestment of what the company said were “non-core” assets.

Transport Infrastructure Ireland would not reveal the total cost of the purchase. A MetroLink station is planned for underneath the former Carlton cinema on O’Connell Street.

In a deal reached last December, TII agreed to buy a row of houses at Dartmouth Square in Ranelagh, beside the Charlemont MetroLink terminus, for more than €30 million.

It has also agreed a reported €22 million deal to buy 40 apartments in the College Gate complex above the Markievicz swimming pool on Townsend Street. The full block of 70 apartments is scheduled for demolition as part of the construction of the Tara Street MetroLink station and further apartment acquisitions are expected.

On Monday, city councillors approved plans for a new €43 million public swimming pool in Ringsend to replace the Markievicz leisure centre. TII will fund the cost of the new pool, said the council.