The appointments were made after an 11-month competitive bidding process, during which seven multi-national bidders were invited to tender for four packages of work.
CH2M will become Phase 2 B development partner and work with teams from Arup, AECOM/Capita /INECO and Mott MacDonald/WSP.
The partners will provide the expert engineering and environmental support needed to advance the development of the lines north of Crewe to Manchester, and from the West Midlands to Yorkshire.
An enabling bill which will contain the planning application for these parts of the high-speed project is expected to be presented to parliament in 2019.
Subject to refinements which are currently under consultation, the government has given the go ahead for the sections between Crewe and Manchester, and Birmingham and Leeds, via the East Midlands and Sheffield.
Phase 2B is due to be completed in 2033.
For the latest project updates from around the globe, subscribe to IRJ Pro.