A plum piece of media business is up for review: Yum Brands' Taco Bell is searching for a new partner to help it with media-planning duties, Ad Age has learned.

The business had been handled by Interpublic's DraftFCB, Taco Bell's lead agency, and it is understood the agency would not participate in the review. A spokesman referred calls for comment to the restaurant chain.

It was not known whether a consultant is overseeing the review, but Santa Monica-based consultant Select Resources International oversaw the Taco Bell digital review earlier this year, which went to Publicis Groupe 's Digitas. WPP's MEC will continue to handle media buying; Digitas, the chain's digital agency of record, handles digital media planning.

Not only is the search for a new media-planning shop a compelling brand opportunity for shops -- in a year that hasn't seen many media reviews -- Taco Bell is also a sizable ad spender.

Parent Yum Brands ranked as the 50th-largest national advertiser last year, according to the Ad Age DataCenter, with total spending of $835 million. Of that amount, it devoted the most to Taco Bell, followed by Pizza Hut, then KFC.

The search has been initiated by Brian Niccol, chief marketing and innovation officer at Taco Bell -- a new role he was appointed to one year ago following a stint at Pizza Hut.

"DraftFCB continues to be our lead agency, and we're extremely proud of their creative work," Mr. Niccol said in a statement to Ad Age .

He went on to describe why the restaurant is looking to shake up its media-agency strategy. "Over the last few months we have been working with our franchisees to set the brand up for success over the next 50 years -- specifically how we can lead and maintain leadership in traditional, social and digital media," Mr. Niccol said. "These include two-step changes that will position Taco Bell for growth. The first is how our media is spent, which includes a new agreement that shifts from local to national, includes Hispanic and more digital. Second is our media strategy. To build off our current success, we are actively looking for an agency partner to help us with national media-planning strategy."

Although DraftFCB is maintaining much of its Taco Bell business, the departure of this piece of the account -- along with the loss of the digital account to Digitas -- signals the relationship may not be as strong as it once was.

Taco Bell is also especially important to DraftFCB after losing the entire MillerCoors account earlier this year, as well as SC Johnson last year and much of the Kraft business -- all accounts that were won by predecessor agency Foote Cone & Belding. Notably, Taco Bell, along with Yum sibling KFC, is one of the last major creative accounts from the FCB era. Wins the agency can tout have included Cox and Discover.

It may not be the last of the moves on the account either. Several executives familiar with the matter said that other roster agencies and Interpublic shops are being considered for additional potential Taco Bell assignments. Taco Bell did not respond to questions regarding the matter.

From a creative perspective, DraftFCB has some reprieve given special promotions have helped Taco Bell improve sales this year, after a slumping 2011. That was thanks in large part to its Doritos Locos Taco, its largest product rollout ever. The chain also this year rolled out its upscale Cantina menu.

The Taco Bell account is handled largely out of DraftFCB's Orange County office. The agency's other big piece of Yum business, KFC, is handled out of Chicago. Much of DraftFCB's New York office is in the health-care business, though that shop earlier this year won the Sea World account.

Contributing: Alexandra Bruell