As part of the deal, the environment consulting firm will submit a planning application for next phase development of the project.
The award follows SLR offering support to GTE in receiving planning permission for the heat plant element of a project, which includes the drilling of two 3,200m deep boreholes and the construction of an underground heat plant.
SLR principal planner Alan Mitchell said the company is delighted to continue its long running relationship with GTE and extend its involvement with the Manchester.
"This geothermal project is an innovative green energy development that has the scope to be replicated across the UK in similar urban environments and areas with similar geology," Mitchell added.
SLR has also been asked to complete a number of environmental studies and submit the planning application for a district heating network.
The new heating network will connect the proposed heat plant site in the Ardwick area of Manchester to the Oxford Road corridor and the city centre.
