The deal will be conducted via a scrip scheme of arrangement, with SRG shareholders to receive 2.479 GCS shares for every one share held.
GCS shareholders will hold 51% of the combined entity, with SRG investors holding the balance.
The enlarged company, to be known as SRG Global, is expected to have a pro-forma market capitalisation of around A$322 million, revenue of $510 million, cash of $36 million, net tangible assets of $200 million, and a global workforce of 2000.
GCS chairman Peter Wade - who is also chairman of Mineral Resources - will remain in the role, with SRG chairman Peter McMorrow as his deputy.
SRG managing director David Macgeorge will be MD with GCS MD Enzo Gullotti as an executive director.
SRG is based in Subiaco, near Pert...