The water company has agreed two-year early contractor involvement deals with a Costain, Veolia, Atkins joint venture and a Balfour Beatty, Skanska and MWH Global team.

After working on the ECI deal, the two consortia hope to later each agree a five-year contract to deliver the AMP6 capital programme from 2015 to 2020.

The contract may then be extended for a further five years from 2020 to 2025, as part of AMP7.

Thames Water is trying alliancing for the first time after seeing programme outcomes from Anglian Water’s @oneAlliance.

Under the new alliance model, Thames Water has brought together two design and build consortia, a programme manager and a technology and innovation provider.

The programme manager job has gone to MWH UK and IBM will be the technology and innovation partner.

Balfour Beatty chief executive Andrew McNaughton, said: “We’re very pleased to be an integral part of Thames Water’s AMP6 cycle at a time when the company adopts a completely new approach to its capital investment.”

Andrew Wyllie, Chief Executive of Costain, said the deal was expected to be worth around £650m to Costain over the AMP6 period.

“The award is a consequence of our ability to work collaboratively, deliver sustainable innovative solutions to major infrastructure needs, and provide value for money. It also further reinforces Costain’s position as one of the leading UK engineering service providers in the water sector.”

As an olive branch, Thames Water has said that contractors that failed to make the Top Tier Alliance will be able to bid for work packages at a later stage, under separate tender competitions.

Consortia including Galliford, Morrison, Mott MacDonald; Laing O’Rourke, Imtech, Barhale; and Murphy, Black and Veatch, Aecom were shortlisted bidders.