NEW YORK (CNN/Money) - A public interest group is suing McDonald's, charging the fast food chain with false advertising due to its promise in 2002 that it would cut the "bad" fat used in its cooking process.

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The group BanTransFats.com, Inc., a California not-for-profit group, filed a federal lawsuit in San Francisco Thursday, charging the company's delay in its promised reduction of trans fatty acids in its cooking process constitutes false advertising.

The group said it is not seeking any monetary damages.

"BTF is asking the court to order that McDonald's take effective steps to inform its customers about its failure to make the change," said a statement from the group. "BTF is also asking that McDonald's make the change to the new cooking oil as soon as possible, just as it promised and represented to the public."

McDonald's announced in September 2002 that it would use an "improved cooking oil" to significantly cut trans fats in the deep fried products on its menu, such as french fries. It said at that time it would cut trans fatting acid levels in its french fries by 48 percent, reduce saturated fat by 16 percent and dramatically increase polyunsaturated fat by 167 percent.

It said it expected to complete the changes by February 2003. But on Feb. 28, 2003, it issued a statement saying it was extending the time it would take to make the change, and it did not give any new deadline or target date.

"While speedy implementation is an admirable goal, we are most focused on the satisfaction of our customers and the quality of our products," said a statement from Ralph Alvarez, McDonald's U.S. Chief Operating Officer at that time.

McDonald's (MCD: Research, Estimates) could not immediately be reached about the lawsuit Friday.

The group said the suit does not have anything to do with obesity. It said trans fats cause serious medical health problems other than obesity. It cited a Harvard School of Public Health which estimated 30,000 or more premature heart disease deaths are caused each year by trans fats.

The same group filed a suit against Kraft Foods (KFT: Research, Estimates) in April, seeking a court injunction that it stop marketing and selling Oreo Cookies to children in the state of California, until such cookies contain no partially hydrogenated oil or other trans fat.

Kraft announced soon after the suit was filed that it would move to reduce or eliminate the trans fat in the Oreo, and the group subsequently dropped its lawsuit.