Consultants will work on development of high-speed line branching north of Birmingham to Manchester and Leeds

HS2 has hired four consultants to deals on the second phase of the £55bn megaproject worth up to a combined £520m.

The client has confirmed CH2M for the £170m development partner role, as tipped by Building, and picked Arup, an Aecom, Capita and INECO joint venture and a team of Mott MacDonald and WSP for professional services roles worth up to £350m.

The winners will work on the development of the high-speed line branching north of Birmingham to Manchester and Leeds.

CH2M saw off American rival Bechtel and a joint venture between Mace and Turner & Townsend (T&T), while an Atkins and Arcadis joint venture missed out on the professional services lots.

Alison Munro, HS2 managing director for development, said: “This contract awards mark an important milestone for HS2 - giving us the expert resource needed to progress the second phase of the project and bring high speed rail to Manchester and Leeds by 2033.

“Our new partners bring a wealth of recent experience on some of the world’s most challenging and complex infrastructure projects and I look forward to working with them to ensure that HS2 can benefit from the experience and innovation they have to offer.”

CH2M’s win is likely to prove controversial coming soon after HS2 Ltd’s appointment of CH2M European managing director Mark Thurston as its chief executive last month, after the client’s previous boss Simon Kirby left last September for an executive role at Rolls-Royce.

Thurston will replace interim HS2 Ltd chief executive Roy Hill, who was himself seconded to the client from CH2M and will return to the engineer.

CH2M – which has been the subject of press speculation of a possible £3bn merger with Atkins – also won the £350m contract to be engineering delivery partner on phase one of the HS2 megaproject last spring, in joint venture with Atkins and Spanish engineer Sener.

Responding to the risk of conflicts of interest in Thurston’s new client role, HS2 Ltd chairman Sir David Higgins said earlier this month Thurston will “cut all links” with CH2M before starting his new job.

He added: “[CH2M] will be treated in the same way as any other supplier - no more or less favourably than that.

“All those who bid for work with HS2 have the right to know that they will be treated on the same basis and, as we have shown to date, we are determined that our systems are constructed in such a way as to deliver that equal treatment.”