Bids will be invited for the operation of the Ring Line and lines to the southeast of the city under a 15-year concession, which will begin when the current contract expires at the end of 2017. Full details of the tender will be published in June.

The cost of tendering these lines could be up to €1.2bn, of which €600m would be for new trains. The Senate asked DB Regio if it would be willing to sell the existing train fleet but DB declined to do so.

The Berliner Morgenpost reported recently that tendering the entire network would cost the city and the state a total of around €3bn, but this option was rejected for legal reasons.