Merseytravel has begun the procurement process to replace the Merseyrail fleet of trains at a cost of up to £300m.
Head-hunters have been appointed to draw up a list of candidates for the post of project director to deliver the procurement.
Merseytravel has been looking at ways to replace the ageing fleet of trains on the Merseyrail network for some time, and recently sought expressions of interest from manufacturers worldwide.
This latest development formally kick-starts the scheme, that should see new trains delivered by 2017. It is anticipated that the formal tendering process will begin later this summer.
The current fleet of class 507 and 508 trains were built in the late 1970s and despite a full overhaul programme in the past decade, both the expected lifespan of the vehicles and the current leasing arrangements are set to expire over the next six years.
Cllr Mark Dowd, chairman of Merseytravel, said: "The Merseyrail rolling stock replacement project will be one of the most significant schemes undertaken by Merseytravel over the next few years, with consequences that will extend for decades.
"Getting the right person to oversee the project and creating the right project governance arrangements are the first priorities on the way to successful delivery of new trains for Wirral and Northern Line passengers."
The Governance arrangements include the establishment of several key project groups that incorporate local elected representatives, Merseyrail, and members of the Liverpool Local Enterprise Partnership and of other regional stakeholders such as Passenger Focus and Merseytravel's Customer Forums.
Merseytravel is the operating name of the Merseyside Integrated Transport Authority and Passenger Transport Executive.