Anheuser-Busch InBev has high hopes that new agency Wieden & Kennedy can turn around Bud Light, which suffered through another tough sales period in the third quarter. CEO Carlos Brito repeatedly invoked the agency's name on an earnings call Friday and foreshadowed what he described as a "revolutionary" campaign for the nation's largest brew that is expected to debut in the coming months.

He called W&K an agency "with an amazing track record" and said it is "the kind of agency and business partner … that we need to deal with such a huge brand in such a fragmented market." The shop's "initial work is very promising and we're looking forward to introducing revolutionary, new creative early next year," he added.

It is unusual for A-B InBev to call out ad agencies on its earnings calls -- especially to the degree that Mr. Brito did with W&K on Friday. But the brewer is relying on the shop to provide a much-needed boost to Bud Light, whose sales have historically been driven by stand-out marketing when it is at its best.

Bud Light's sales-to-retailers fell by "low single digits" in the third quarter in the U.S., A-B InBev reported. The brand lost 0.45 share points, bringing its total share loss for the first nine months of the year to 0.35 points. At the end of 2014, Bud Light controlled 17.5% of the U.S. beer market, more than double the share of its closest competitor, Coors Light (8.2%), according to shipment data from Beer Marketer's Insights.

W&K, New York, won the Bud Light account in July after the brewer cut ties with BBDO, New York. Under W&K, Bud Light will end its nearly two-year-old, millennial-focused "The Perfect Beer for Whatever Happens" campaign. New ads will target a broader age group, A-B InBev U.S. Marketing VP Jorn Socquet said in a recent interview. The brewer has not revealed creative details on the new campaign. But Mr. Socquet said ads would include celebrities and would break as early as December or as late as during the Super Bowl in February. Bud Light is also expected to make packaging changes.

"Up For Whatever" positioned Bud Light for spontaneous fun and included such stunts as branded town takeovers. The campaign had moments of success -- Bud Light grew share by nearly a full point in the third quarter of 2014 in the light beer segment the brewer noted Friday -- but failed to provide lasting momentum.

Mr. Socquet suggested that the campaign was trying too hard to appeal to young adult drinkers. "Bud Light as a brand appeals to everybody. And everybody who is young at heart should be attracted to Bud Light, not just [young adults]," he said in the mid-October interview.

For the quarter, A-B InBev reported total global revenue of $11.38 billion, down from $12.24 billion in the year-earlier quarter. Revenue grew by 7.9% on an organic basis, which accounts for currency fluctuations.

Bright spots included Budweiser and Stella Artois, which grew global volumes by 11.5% and 12.9% respectively. In China -- where Bud's marketing has been linked to electronic dance music -- volumes for the so-called King of Beers are up double digits year-to-date, Mr. Brito said.

Budweiser is now bigger globally than it is in the U.S., according to A-B InBev. That is a positive sign for the brewer, which has visions of turning the brew into the Coke of beers globally, where beers brands have traditionally been built on a regional basis. The brand's footprint could grow even bigger if the proposed A-B InBev merger with SABMiller is finalized. Bud's global agency is Anomaly.

In the U.S., Budweiser continues to mount a bit of a comeback after many years of significant declines. Bud lost 0.15 share points in the first nine months of the year, the brewer reported. That compares with an estimated 0.3 point share loss that A-B InBev reported for 2014.

Mr. Brito cited Bud's "Brewed the Hard Way" campaign that broke during the 2015 Super Bowl. Ads have proudly declared the nation's third-largest beer as a "macro" brew, while putting more emphasis on the liquid and even taking a few shots at craft beers. "The brand went back to talk about its heritage and quality," Mr Brito said. That "made a difference," he added. "Macro we stand -- that's Budweiser."

The brewer's hottest brand in the States is Michelob Ultra, which posted double-digit volume growth in the quarter, A-B InBev reported. The brew is "the fastest-growing brand in the country by absolute volume so for this year," Mr. Brito said. Ultra -- whose agency is FCB, Chicago -- grew sales by 18.4% in the 52 weeks ending Oct. 4 and is ranked as the nation's 7th-largest brew, according to IRI, which does not include bar sales.

Weak spots for A-B InBev include its Rita's franchise of flavored malt beverages that are part of the Bud Light megabrand. Mr. Brito called Ritas sales this year "disappointing," citing stiff competition in what he described as the "near-beer segment." Competing flavored beer brands include MillerCoors-owned Redd's Apple Ale, which like the Ritas franchise includes several different flavored versions including strawberry and green apple.

On the call, Mr. Brito teased a new line extension for Ritas called "Splash," which he described as a "low-alcohol line extension available in glass." FCB handles advertising for the Ritas franchise

A-B is also trying to boost its presence in the Mexican import segment, Mr. Brito said. Mexican brews -- led by Constellation Brands-owned Corona -- have been on fire as of late. A-B InBev began selling a Mexican import called Montejo last year, but it remains a niche player. "We've made a start with Montejo," he said. "But there's a lot more to be done."