ATLANTA (AP) — Coca-Cola Co. reported quarterly sales that fell short of Wall Street estimates on Tuesday as demand remained weak for Diet Coke in North America.

Globally, the world's biggest beverage maker said sales volume rose 3 percent, boosted by gains in places including the Middle East and South Africa.

In its flagship North American market, sales volume was flat. Although sodas including Fanta and Sprite saw gains in the region, sales of Diet Coke remained soft. Executives at Coca-Cola and PepsiCo have noted that diet sodas have been suffering because of concerns about artificial sweeteners. To address that, the companies have been working behind the scenes to assure consumers about the safety of such sweeteners.

Coca-Cola also plans to eventually introduce a version of its namesake drink that's naturally sweetened with stevia in the U.S. The drink, Coca-Cola Life, has already hit shelves in other markets, including Argentina.

The company also noted that juice drinks saw declines in North America during the quarter, as higher prices scared off some customers.

For the quarter, the Atlanta-based company said profit fell to $2.6 billion, or 58 cents per share, from $2.68 billion, or 59 cents per share, in the same quarter a year earlier.

Excluding one-time items, it earned 64 cents per share, which was a penny more than analysts expected.

Revenue dropped 1.4 percent to $12.57 billion. Analysts expected $12.85 billion, according to Zacks.

Coca-Cola's stock was down 55 cents, or 1.3 percent, at $41.85.

Its shares have risen $1.09, or 2.6 percent, to $42.40 since the beginning of the year, while the Standard & Poor's 500 index has increased 6.8 percent.