Abellio Great Anglia, a unit of Nederlandse Spoorwegen, will run the franchise across parts of Essex, Norfolk, Cambridgeshire and Sussex, including many of the key routes in London for the 2012 Olympics.
Abellio will run the Greater Anglia lines from 5 February for 29 months on a short-term basis, with the franchise up for renewal again in July 2014.
At that time, a 15-year deal for the area is expected to be agreed.
Abellio will take on the maintenance of certain rail stations and ticket facilities, with requirements for services to be improved during its tenure.
It already runs trains in the UK in partnership with outsourcing firm Serco.