Nexus, which owns and manages the light rail system used by more than 40 million passengers a year, said it would now finalise details with Deutsche Bahn's DB Regio unit on a contract for seven or nine years from April 1, 2010.
State-owned Deutsche Bahn, which operates in 150 countries and already owns a stake in Britain's Chiltern Railways, said it expected the contract to be finalised by mid-January. No financial details were released.
Last month Deutsche Bahn, which also operates bus services in other European countries, won a contract to run a local train network in the Swedish region of Oestergoetland from December 2010.
In addition to commuter services between London and Birmingham, Deutsche Bahn also operates trains in the Greater London area and non-stop services between London, Wrexham in Wales and the county of Shropshire.
"We were chosen by Nexus in preference to eight other competitors, including major European transport groups. This once again emphasises our position as a leading European local transport company," Deutsche Bahn said in a statement.