Mon May 16, 6:34 PM ET CHICAGO - Healthy french fries might seem like anoxymoron, but McDonald's said it is trying to make good on an almost3-year-old promise by testing a healthier blend of oil for its signaturefries at a small number of restaurants.

The company would not disclose the location or number of restaurants atwhich it is testing the cooking oil. A company spokesman said it isgauging customer feedback but wouldn't say what the response has been.

"We're continuing to test in a small number of restaurants," McDonald'sspokesman Walt Riker said Monday. "It's important for our customers andwe'll continue to test to get it right."

McDonald's in September 2002 vowed to switch to a new oil that would halvethe level of harmful trans fatty acid in its fries. But it delayed thoseplans in February 2003, citing product quality and customer satisfactionas priorities.

Riker said the company has been testing a new frying process in a smallnumber of stores ever since.

Trans fat is produced when manufacturers add hydrogen to vegetable oil - aprocess called hydrogenation. It raises the body's level of arteryclogging cholesterol.

The Oak Brook-based company already has reduced the amount of trans fat inits Chicken McNuggets, Crispy Chicken and McChicken sandwiches, Rikersaid. It also has been adding healthier menu items like a fruit and walnutsalad in response to consumers' changing eating habits.

But rolling out a new cooking oil for its fries could pose a risk to salesof one of McDonald's most popular menu items, said Janna Sampson ofOakbrook Investments, which owns more than 1 million McDonald's shares."It's hard to imagine they can do that without some effect on the taste ortexture of the fries," she said.

"I just don't think the people buying fries care that much" about transfat, Sampson added.

Analyst Carl Sibilski of Morningstar said he thinks it makes good businesssense to test the cooking oil at a limited number of restaurants and gaugecustomers' reaction.

"It sounds like a really smart marketing move not to make a big deal outof it," Sibilski said. "If they came out and said it's new oil, peopleprobably would think the fries taste different regardless."

Food and farm products conglomerate Cargill Inc. is a major supplier toMcDonald's for its cooking oil, the privately held Minnesota companyconfirmed Monday, but it declined to answer specific questions about itsinvolvement in testing.

In February, McDonald's agreed to pay $8.5 million to settle a lawsuitfrom a nonprofit advocacy group accusing the company of misleadingconsumers by announcing plans to change its cooking oil but then delayingthe switch. The bulk of the settlement went to the American HeartAssociation to educate the public about trans fats in food.

McDonald's also agreed to pay $10 million in 2002 to settle a lawsuitbrought by vegetarian groups that had sued after it was disclosed that itsfrench fries were being cooked in beef-flavored oil during the 1990sdespite the company's insistence it was using pure vegetable oil.