A shortlist of four agencies, including the incumbent H&K, will present to GM's marketing team early next month.
The prize is one of the most lucrative PR briefs in the region.
The winning firm will handle GM's business across the Gulf and Levant, representing brands including Chevrolet, Cadillac and Hummer.
Saada Hammad, regional communications and PR manager for GM Africa and Middle East, declined to name the other three agencies, but said: "They are the biggest in the market who have no conflict of interest."
She added: "It is important that the team that will work on our business has the knowledge and the passion for cars as well as the understanding of how we come to market.
"Another key area is media relations and (the ability to) counsel us on how we maintain our presence or improve our presence in the media in a positive way."
Hammad told Campaign Middle East earlier this year that GM's business would be lucrative for a PR agency. "We've just grown 24% from 2005 to 2006 and we are one of the biggest players in the region," she said.