Burger King has not been getting its way when it comes to its advertising agency partners of late -- and so it's looking to add some new shops to the mix, Ad Age has learned.

Industry executives say Burger King has quietly been sniffing around with shops in adland that aren't conflicted in the fast-food category and could potentially take on project work for the chain. What's more, it's already handed project work to one new shop, San Francisco-based Pereira & O'Dell, a move that suggests it's serious about finding new additions to its roster and fast.

Pereira & O'Dell -- which is owned by Brazilian marketing services giant Grupo ABC -- was asked in short order to create a TV spot promoting 50-cent soft-serve ice-cream cones through August 31. The shop was not previously on the chain's roster, and it's unclear what other assignments the agency will be creating for Burger King going forward.

Burger King didn't respond to a request for comment and Pereira & O'Dell declined to comment. But these moves are a sign that incumbent shops McGarryBowen and Mother should be aware that the roster is getting increasingly crowded, which could spell uncertainty for them. Both agencies declined to comment.

What's curious about the timing of the moves is that the fast feeder has actually been showing signs of stemming a long-running decline in same-store sales.

After a protracted period of sales decline in which it fell behind Wendy's to become the No. 3 burger chain in the U.S., Burger King in the second quarter posted a systemwide same-store sales bump of 4.4% globally, including a 4.4% spike in the chain's U.S. and Canada business. During the second-quarter conference call, Burger King North American President Steve Wiborg pointed to marketing and new menu items as significant contributors. Mother 's campaign ran during much of the second quarter, but Mr. Wiborg did not credit a specific agency.

Still, some cracks in the relationships with those shops have already become evident. Months after Burger King named McGarryBowen its lead creative agency last year, the chain began making it more difficult for its lead shop to get work by adding independent Mother , as well as Ogilvy offshoot David, to its general-market roster. It also tapped Pitch, which had already been handling the kids marketing, as an official general-market roster shop.

The move meant that the agencies would have to compete against one another, which has been happening more or less each quarter, for each new campaign.

That news is surely unfortunate for McGarryBowen, which originally signed on with Burger King as the main agency in 2011. McGarryBowen hasn't had any work run since the end of the first quarter, after Burger King announced that it was adding Mother , David and Pitch as general-market agencies.

In the second quarter, Mother 's celebrity-laden campaign ran for much of that period. (That had its own set of issues thanks to the Mary J. Blige ad that was yanked out of rotation after being criticized for reinforcing African-American stereotypes.) David's campaign that promoted Burger King's barbecue products ran earlier this quarter.

As Burger King continues to shop around for agency partners, one thing it may want to consider is that many prominent shops will be reluctant to take on business solely for project work, as it will conflict them out of larger opportunities in the fast-food category.

Contributing: Rupal Parekh