Transport for London (TfL) has applied to take over the services run by Tube infrastructure company Metronet, which has gone into administration.
The formal expression of interest was made to the Metronet administrator and is on a temporary basis.
Metronet, which is responsible for maintaining and enhancing two thirds of the London Underground (LU) network, went into administration last month after experiencing cost overruns.
Metronet and the other private Tube infrastructure company Tube Lines were set up when the 30-year Underground public-private partnership (PPP) scheme was created in 2003.
TfL's formal offer, which could see it take over for two years, could be made by the end of next month.
LU managing director Tim O'Toole said: "In dealing with the collapse of Metronet, and through the administration process, we have had two key priorities.
"First, to ensure the continued safe and reliable operation of the Tube network for passengers. That has been achieved and I would like to pay tribute to the hard work and dedication shown by all Metronet and LU as well as the administrator and his team. We need to continue to work together for passengers.
"Secondly, following administration, we seek to put in place a stable, economic and efficient structure that is better able to deliver TfL's investment priorities that will lead to increased capacity on the Tube in future, along with station security and communications improvements.
"We strongly believe that the best and most robust way to achieve our ultimate goal is for an early exit from the administration process, to enable TfL to maintain the continued safe operation of the Tube network and to mitigate the performance and cost risks that inevitably come with such a situation."
TfL said it is now working with the administrator on a formal bid and that more details would be made available when they were confirmed.
