Atkins could become part of Canadian consultant SNC-Lavalin by early July if all parties agree to the takeover.
In an internal email seen by New Civil Engineer, Atkins chief executive Uwe Krueger set out a number of key dates in the run up to completion of the £2.1bn deal which was announced in April.
For the deal to go through, shareholders will vote at two separate meetings, a court meeting and a general meeting both of which will take place in London on 26 June.
Assuming shareholders approve the deal, it must then be sanctioned by the High Court. Currently this is expected to take place on 29 June.
Following High Court approval, Atkins is expected to be officially acquired by SNC-Lavalin by 3 July.