Balfour Beatty and Laing have been selected to work with the hospital's project team before one of them is chosen as preferred bidder by Alder Hey's Trust Board.
Both have been shortlisted for the £288m Alder Hey Children's Health Park Project in Liverpool.
Laing is heading the Acorn Consortium which brings together Laing Investments, contractors Laing O'Rourke with Interserve, and architects BDP.
Balfour Beatty is working with Anshen and Allen, the London firm of architects which specialise in health care developments. Lead directors on the Alder Hey scheme are Ileana Alexandratos and Derek Parker.
One of the consortia will build a paediatric health facility, the Alder Hey Children's Health Park, which is set to be the first of its kind in Europe.
A network of wards, built 100 years ago to the design of Florence Nightingale, will be replaced by the new facility.
The health park is being built on a new greenfield site adjacent to the current hospital. The site forms part of Springfield Park, owned by Liverpool City Council. The council has given outline planning permission for the children's health park, centred around a 450,000 sq ft hospital and 1,200-space car park.
The Trust held a Bidder Open Day at the hospital in February and Alder Hey announced that five consortia, comprising over 30 different companies, had registered bids to deliver the children's health park.
Although the full scheme will cost £288m, the estimated overall capital value of the project relating to the Trust's recently published Official Journal of the European Union notice is in the region of £175m, which includes traditional and private finance initiative–funded components at current day prices.
Alder Hey, in the West Derby area of Liverpool, is one of the largest specialist children's hospitals in Europe covering a total catchment population of 7.6m and delivering over 244,000 episodes of care a year. The hospital is a designated University of Child Health Institute, and one of only two trust's in the North West to be a formal provider of children's specialised services, with 30 specialities in 50 departments, according to the NHS.