The recalculation follows the restructuring of GM during the bankruptcy process, allowing a new General Motors company to emerge free of many of GM's former obligations.
Publicis said: "Since the filing of the bankruptcy, Old GM has signed agreements with some of our agencies and assumed and assigned contracts with other of our agencies to New GM.
"As a result, we have received payment of the bulk of our fee receivables as of the date of the bankruptcy, and GM has committed to pay us our remaining pre-petition fee receivables over the next few months."
Publicis is due to publish its second quarter financial results tomorrow.