NEW YORK — Pepsi is offering a new low-calorie version of Gatorade in an effort to keep customers who have strayed from the sports drink in search of lower-calorie drinks.

PepsiCo Inc., which announced plans for the low-cal G2 version of Gatorade yesterday, and its bigger rival, The Coca-Cola Co., are aggressively competing for sales of non-carbonated beverages as health-conscious consumers shy away from carbonated soft drinks.

PepsiCo, the nation's second biggest soft drink company, said in July that its sales of carbonated soft drinks fell 4 percent in the second quarter while non-carbonated drinks grew 3 percent.

Last year, non-carbonated beverages accounted for 69 percent of PepsiCo Beverages North America's $9.57 billion in 2006 revenue, more than double that from soft drinks that made up 31 percent of the unit's total.

"G2 should help limit the downside risk to a Gatorade slowdown," Morgan Stanley analyst Bill Pecoriello told investors in a research report.

Gatorade sales slowed in the second quarter after a 2 percent to 3 percent price hike in March and in comparison to sales that had grown 29 percent a year earlier.

PepsiCo said G2 will have 25 calories per eight-ounce serving and is the first new Gatorade product since the original drink was introduced in 1967. The original lemon-lime Gatorade has 50 calories per eight-ounce serving.

Purchase, N.Y.-based PepsiCo said it will distribute G2 starting in December to convenience stores, gas stations and retail outlets. The new Gatorade will come in three flavors: fruit punch, grape and orange.

PepsiCo also announced yesterday that it would introduce a bottled water with caffeine and vitamins called Propel Invigorating Water; reformulate its SoBe Life Water with sucrose, antioxidants, vitamins and fewer calories; and use a new sweetener blend with fewer calories for its Aquafina Alive water.

In June, Coca-Cola bought VitaminWater maker Glaceau for $4.1 billion, a price tag that signaled the company's seriousness in pursuing growth of non-carbonated beverages.

Since then, the company has also given its Glaceau management team control of its Powerade sports drink brand, which competes directly with the more popular Gatorade.