Major U.S. beverage companies -- PepsiCo Inc. (NYSE:PEP) and Coca-Cola Co. -- want to market stevia-sweetened products once the sweetener gets approval, the Chicago Tribune said. Agribusiness giant Cargill Inc. already has a stevia-based sweetener in grocery stores, and Chicago-based Merisant Co., maker of the popular sweetener Equal, soon will do the same, the newspaper said.

But some public watchdogs, including the Center for Science in the Public Interest, are raising concerns about potential cancer-causing properties of stevia. The center is urging the FDA to do more testing before granting approval, the Tribune said.

Native to South America and already used as a sweetener there, Japan developed stevia-based sweeteners several decades ago, and Australia has recently approved it.

But stevia sweeteners are still banned in much of Europe.

As a sweetener it developed an unpleasant licorice taste that researchers have had trouble erasing, the Tribune said.