However, Transport for NSW would not confirm how many companies attended, nor if any were foreign-based.

In August, Roads and Freight Minister Duncan Gay said the government would look to private investors to build the 35-kilometre rail line that would start from Maldon and head south to join the Moss Vale-Unanderra line at Dombarton.

The window for registration of interest (RoI)  from the private sector was opened on October 13 and any interested parties have until February 25 to lodge an application.

Then those applications that best address the selection criteria will be invited to submit a formal tender.

The project would be fully funded by the private sector and no government money would be contributed towards the construction.

As part of the RoI process a briefing session was scheduled for today, but government officials would not confirm its location or time.

‘‘The briefing covered technical and procedural information about the RoI and gave prospective proponents the chance to ask any questions about the RoI process,’’ a Transport for NSW spokeswoman said.

She also declined to offer  details on the attendance at Thursday’s briefing.

‘‘Transport for NSW will hold all submitted information as commercial-in-confidence and does not intend to disclose any information submitted by interested parties to third parties without their consent and this extends to the number of attendees or their identity at today’s briefing session,’’ the spokeswoman said.

However, when the RoI closes in February, the names of those parties that have submitted registrations will be listed on the  NSW government’s tendering website.