General Mills has hired hometown agency Olson of Minneapolis to handle a sizeable campaign for Yoplait Greek yogurt, which will relaunch next month with a new formula, packaging and messaging.

Saatchi & Saatchi, New York, the incumbent shop for Yoplait, will remain on the brand for regular yogurt varieties. But General Mills picked Olson to oversee the launch of what is being described as a "full-calorie traditional" Greek yogurt that will debut in July, replacing the marketer's existing Greek version. The restaging comes as the marketer seeks to gain momentum in the fast-growing Greek segment, where it has lagged. "This product's point of difference is its superior taste," CEO Ken Powell said on an earnings call Wednesday.

While Olson is already on General Mills' roster, the Yoplait Greek win represents its highest-profile piece of business from the marketer. In a statement to Ad Age, General Mills said that it "primarily works with two large advertising agency partners -- Saatchi and McCann Erickson. Historically, we also partner with other advertising agencies on special brand projects. We have worked with Olson in this way in the past, and elected to work with them for the new Yoplait Greek campaign." (Olson's other assignments include smaller yogurt brands Liberte and Mountain High, as well as digital/social for Yoplait.)

The new yogurt is likely to get a significant ad push, including TV, as General Mills looks to make up ground in the Greek segment. The change marks the third time General Mills has changed its Greek variety since entering the segment in early 2010. A spokeswoman characterized the latest effort as a new product with new packaging and a new message, contrasting it with previous changes, which she said were "more about improving or enhancing the existing product."

The marketer's stumbles in Greek have hurt the overall Yoplait brand, which was recently surpassed by Dannon as the total yogurt market leader. In Greek, both of the yogurt giants have been playing catch-up to Chobani, which got an early start in the segment in 2007.

General Mills' U.S. Yoplait division had a net sales decline of 5% to $1.35 billion in its fiscal year ending May 26, the company reported Wednesday. That marked the steepest decline among its seven U.S divisions. (Big G cereal sales fell by 2%, and frozen foods dropped by 3%, while snacks gained a healthy 9%.) Total U.S. net retail sales grew by 1% to $10.6 billion, while global net sales increased 7% to $17.8 billion. U.S. advertising and media expenses for the year came in 5% below "strong year-ago levels," the company reported.

On the earnings call, Mr. Powell said the company expects to return the cereal division to growth with a "stronger new product lineup and stronger advertising." New products include Hershey-branded "Cookies 'n' Creme" cereal. General Mills already markets "Reese's Puffs" cereal.

Mr. Powell told analysts that "we are disappointed that we didn't have sales growth this year in the Yoplait division." But he added that "the sequential trends for the business ... are quite encouraging." He singled out Yoplait Greek 100-calorie, launched last year, as a "clear success" with year one sales expected to top $140 million. The launch campaign for the low-cal variety was handled by Saatchi. It is unclear if Olson will pick this up too, or if it will remain at Saatchi.

General Mills last reformulated its Greek yogurt in 2011, giving it a thicker texture, new flavors and brighter-colored packaging. The new version will be "blended," meaning that the fruit is mixed in the yogurt, rather than at the bottom. Mr. Powell described it as a "filtered traditional Greek yogurt" that has an "absolutely a terrific taste profile and we believe that that will be very well received by consumers."

The yogurt will fight for shelf space in the increasingly crowded Greek market. For instance, Chobani this week announced 14 new flavors across its Greek portfolio. The brand's "Flip Greek Yogurt" variety - which launched last year featuring crunchy "mix-ins" -- is coming out with four new flavors, including "blueberry power," which includes chia seeds, hemp seeds and walnuts. The flavor was inspired by yogurt served at Chobani SoHo, the marketer's retail store in New York City, the company said.

"We know that the yogurt market in America is just beginning; European consumers eat up to seven and a half times more yogurt per capita," John Heath, Chobani's senior VP-innovation, said in a statement. "So this launch, and every launch for Chobani, is about giving people new and exciting ways of experiencing our Greek yogurt."