Denton Wilde Sapte, Freshfields and Simmons & Simmons have beaten off four firms to win places on the Treasury Solicitor's first Private Public Partnership (PPP) panel.
The firms will handle all PPP government work and will deal predominantly with the Home Office.
The firms won places after undergoing a lengthy tendering process beginning in February, when seven firms were invited to bid for the places.
The panel is only the third such arrangement for projects work within government - the other units are the Ministry of Defence and the Department of the Environment, Transport and the Regions.
Denton Wilde Sapte currently holds places on all three panels. Ed Marlow, head of PFI/PPP practice at Denton Wilde Sapte, says: "In terms of profile it is worth a lot. It reinforces an existing relationship we have with the Treasury Solicitor.
"In terms of financial reward I would hope the fee income that the appointment generates will be consistent with the importance of the appointment."
The department decided to appoint a panel because of the increase in PPP work. It will operate on a three-year trial basis.
Tim Collins, the legal adviser in the Treasury Solicitor's Department who led the tendering process, says:"We have a lot of general commercial experience and a lot of public law expertise in this department, but we lack certain resources to handle the sheer volume."
Prior to the panel appointments, firms were selected on a case-by-case, ad hoc basis using a formal tendering process.
Both Denton Wilde Sapte and Freshfields have worked on individual projects for the Treasury Solicitor in the past while Simmons & Simmons has been a major player in project work through long-standing client Railtrack.
Marlow: Denton Wilde is one of three firms to win a panel place