The stadium's client, Manchester council, confirmed that it would be retaining Laing, adding that the contract had been signed.
Council leader Richard Leese said: "As far as I am concerned, Laing will be staying on the project." Laing insiders said that it was unlikely that there would be big changes at the group until the deal was completed next month.
One said: "I cannot see any senior level departures before the end of May. Nothing has been concluded as yet." The unprecedented deal, announced to City and staff last week, would see O'Rourke take over a company four times its size.
It has led to predictions of a major shake-up in the sector, with specialists taking the leading role in construction away from traditional contractors.