While no financial details of the deal were released, Orla officials said M3's Hermosillo, Mexico, office would tackle detailed engineering, construction planning and execution, contractor management and cost control with support from its Tucson, Arizona, location.
Engineering work is scheduled to begin by the middle of this month.
Orla officials confirmed the commencement of the work by M3 at the Zacatecas state site was currently subject to the inking of a definitive agreement.
Camino Rojo, which will centre around an 18,000-tonne-per-day heap-leach open-pit operation once it comes online, has estimated reserves of 44Mt and a mine life of 6.8 years.
Financing discussions for the project continue with various lenders and financiers, the company said.
"Orla continues to progress according to schedule in developing the optimum structure to finance the development," officials said.
Camino Rojo is 100% owned by Orla.