ATLANTA: US soft drinks giants are revamping bottle sizes to inject more fizz into a declining market where consumers are increasingly making healthier choices.

Both the Coca-Cola Company and PepsiCo are testing alternatives to the convenience store staple, the 20-ounce bottle.

Data from industry publication Beverage Digest shows overall soda sales declined 3.5% in the first quarter, while convenience store sales dropped 4.2%.

It is hoped trials by soft drinks bottlers will bring back consumers who have shunned the bigger sizes because of health concerns or cost issues.

Coca-Cola Bottling Consolidated is testing in  around 1,700 convenience stores in Virginia where it has replaced 20-ounce bottles with 16-ounce and 24-ounce bottles.

The idea, says the firm's marketing chief, Mel Landis, is to offer consumers the same choices they might get in a grocery store.

Pepsi Bottling Group is trialling 12-ounce and 16-ounce bottles in some markets.

Declares a Pepsi spokesman: "[It] is about giving consumers more choices, and if that leads to more frequent transactions and greater volume, it's also a win for our customers, our bottlers and us."

Data sourced from Wall Street Journal Online; additional content by WARC staff