Coca-Cola Co. (KO) said Friday it was rolling out a diet version of its Pibb Xtra soft drink in three U.S. states, where it will compete with Cadbury Schweppes Plc's (search) fast-growing Diet Dr Pepper drink.

A Coke spokesman confirmed a report by trade publication Beverage Digest (search) that the world's largest soft drink maker was introducing the spicy cherry-flavored Pibb Zero (search) in parts of Texas, Oklahoma and Kansas.

The states are strong markets for Diet Dr Pepper (search).

But Scott Williamson, a spokesman for Atlanta-based Coca-Cola, said there were no current plans to extend the Pibb Zero rollout nationally.

Introduction of the new drink, which is sweetened with a blend of aspartame and acesulfame potassium, comes amid a restructuring at Coke that is designed to sharpen the company's focus on innovation and reignite sluggish soft drink sales.

The effort began last year when Neville Isdell (search) took over as Coke's chairman and chief executive.

New offerings in the U.S. market include a version of Diet Coke sweetened with the popular sugar substitute Splenda, a diet cola called Coke Zero and the Full Throttle energy drink.

The innovation strategy, however, carries risks. If poorly executed, the new drinks could cut into sales of existing products or simply fail to find a niche among increasingly picky consumers.

Executives in the Coke system, however, say that the new drinks have gained traction since being introduced.

On Thursday Coca-Cola Enterprises Inc. cited unexpectedly strong sales of Coke Zero and Diet Coke sweetened with Splenda as one of the factors that fueled a sharp rise the soft drink bottler's second-quarter earnings.

Shares of Coca-Cola were down 19 cents to $44.20 Friday on the New York Stock Exchange. Cadbury Schweppes was unchanged at 548 pence on the London Stock Exchange.

Coca-Cola Enterprises rose 26 cents to $23.86 on the NYSE.