General Motors is planning to launch reviews for all of its PR agency partners around the globe, with the goal of consolidating with one agency of record per brand.

Tony Cervone, senior VP-global communications for the automaker, said the reviews will "take place for the most part in 2016," except for Cadillac, which will begin before the end of the year.

Each GM brand, such as Chevrolet and Cadillac, will consolidate from multiple PR firms to one global partner, said Mr. Cervone. However, one agency may work on both Buick and GMC.

GM has strong agency support right now, he added, so it's not an issue of underperformance, but rather the fact that the current structure is too complicated. "We're not able to fully take advantage of agencies and their abilities to run effectively and globally counsel us and leverage our skill sets," said Mr. Cervone.

The automaker will invite incumbents, such as Weber Shandwick and MSLGroup, which both do corporate work for GM; FleishmanHillard (Cadillac and Chevrolet) and John Doe (Buick and GMC) among others now on the roster to compete in the reviews.

While Mr. Cervone declined to disclose budgets, he said that they will not be trimmed.

"We're not trying to drive fear into the agency world," he said. "It's really about transforming how we're working with agencies and the way we've historically used agency resources to build on what we do normally day in and day out."

With a more streamlined communications team, Mr. Cervone said the company and its brands will have better message alignment and consistency around the world, which is "more important than ever today."

GM ranked as third largest ad spender in the U.S. according to the latest ranking from the Ad Age Datacenter. In 2014, the company spent $3.12 billion on advertising in the U.S.

Earlier this year, GM was one of a several automakers, including Lincoln, Jaguar, Honda, and Acura, that decided not to advertise during the Super Bowl.