Food & Beverage

Slumping Diet Coke goes Slurpee

More than three decades after hitting the market, Coca-Cola's Diet Coke brand is experimenting with a frozen variety for the first time.

The second-best selling beverage in the U.S. introduced Diet Coke FROST, a low-calorie frozen carbonated beverage, on Wednesday.

Diet Coke Frost
Source: Coca-Cola Company

For now, the cherry-flavored drink will be sold exclusively at 7-Eleven locations. At the end of May, frozen Diet Coke will be expand to other retailers throughout the U.S.

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Diet Coke joins a long list of brands available in Slurpee versions including, Dr. Pepper, Coca-Cola Classic, Pepsi and Fanta.

The move comes a week after Coke reported weaker Diet Coke sales during its quarterly earnings conference call amid a challenging environment for the industry.

Coke's head & shoulders

"Sparkling beverage volume fell 2 percent, largely due to softer Diet Coke volume," said CEO Muhtar Kent, adding that Coca-Cola was moving to address headwinds and misconceptions.

(Read more: Coke matches earnings estimates)

The effort will involve "increase[d] aggressive sweetener innovation, transparent consumer communications, continued packaging evolution and new partnerships with credible third parties around the world who will use meaningful facts to defend and protect the sparkling category," Kent said.

The overall carbonated cola category has also seen pressure in recent years, according to data from Euromonitor. Volume dropped 3.6 percent in the U.S. last year versus 2012. Worldwide, volume growth was flat.

—By CNBC's Katie Little. Follow her on Twitter @KatieLittle.