The Greek yogurt slugfest has spread to the advertising world, with General Mills and rival Chobani gaining a split decision.

Golden Valley-based General Mills, maker of Yoplait, earlier this year launched a marketing offensive against Chobani that featured a classic consumer taste test. Chobani cried foul, complaining to a national advertising self-regulatory group.

On Wednesday, the National Advertising Division (NAD) of the Council of Better Business Bureaus said General Mills could indeed support certain claims for its "Taste-Off" advertisements. But, the ad group said, General Mills also should modify or discontinue other claims against Chobani.

Chobani has the leading Greek yogurt, and has upended the entire U.S. yogurt business over the past five years. Once a niche product, Greek now makes up almost 50 percent of the yogurt market. But traditional yogurt powerhouse General Mills was late to the Greek market, losing sales.

In Yoplait TV ads that began ­running earlier this year, consumers sampled two Greek yogurts, without being told which one was which. One was Yoplait's blueberry, which mixes fruit into the yogurt. The other was Chobani's blueberry, which features fruit on the bottom. Yoplait wins.

Chobani fired back on multiple fronts, arguing among other things that pitting blended yogurt up against fruit-on-the-bottom yogurt was unfair — not an apples-to-apples comparison.

No problem there for Yoplait, NAD concluded. No problem either with Yoplait's contention that nearly two out of three tasters preferred its blueberry-flavored Greek over Chobani's blueberry, NAD said. The ad group found Yoplait used reliable "taste test protocol."

But Chobani also claimed that the overall message of Yoplait's ad campaign was that Yoplait's Greek yogurt is preferred over Chobani's entire lineup, not just the blueberry version. Here, NAD took issue with Yoplait, saying it appeared to make such a broad claim in statements on social media.

Also, NAD concluded that when General Mills offers "material" incentives for product reviews — as it did for Yoplait Greek on social media with $4 gift cards — that the company should advise reviewers to disclose such incentives.

General Mills, in a statement to NAD, said it disagreed with the group's conclusions on both the material incentives issue and the lack of clarity on Yoplait's claims of superiority to Chobani.

However, General Mills said it "nonetheless will take NAD's recommendations into consideration in future advertising campaigns," according to a NAD news release.

In a statement to the Star Tribune, General Mills said it was "pleased with [NAD's] decision. The NAD agreed that our taste-test methodology met all industry standards."

General Mills said it used the same methodology to compare its strawberry Greek 100 yogurt to Chobani Simply 100 strawberry yogurt in a new ad that touts the fact that 80 percent of tasters in the test chose Yoplait.

Chobani didn't reply to an e-mail request for comment.

Mike Hughlett • 612-673-7003