Deutsche Bahn AG Friday said it has signed a billion-euro contract with German utility RWE AG (RWE.XE) for the supply of hydro electricity, without elaborating on the details.

A spokeswoman from RWE said the figure is in the "single-digit" billion euro range.

A Deutsche Bahn spokesman had no further comment.

Details will be presented at a press briefing Monday, as planned, by Deutsche Bahn chief executive Ruediger Grube and RWE chief executive Juergen Grossmann.