A major environmental group yesterday criticized chemical giant Du Pont Co.'s series of "green" advertisements and called the company the nation's leading corporate polluter.

Friends of the Earth President Brent Blackwelder told a press conference that Du Pont's television and print advertisements, which feature barking sea lions and jumping dolphins, are deceptive because they imply the company is making major changes.

"Du Pont's feel-good advertising is a distortion of environmental fact," said Jack Doyle, a senior analyst with the environmental advocacy group that prepared a report on Du Pont.

"In reality, Du Pont is the single largest corporate polluter in the United States," Doyle told reporters.

But Wilmington, Del.-based Du Pont said in a prepared statement that the report does not contain any new allegations.

"It seems to be a rehash of several of Du Pont's most serious environmental challenges -- all of which we are working diligently to resolve," the statement said.

The Friends of the Earth report said Du Pont's total pollution in 1989 was 14 times that of Dow Chemical Co., 20 times that of Chrysler Corp. and 30 times that of Mobil Corp.

Among the nation's top 10 corporations in 1989, Du Pont had the highest ratio of pollution to profit, 14 percent, the report said.

"It's morally reprehensible to portray this type of image {in advertisements} when they have this type of track record," said Blackwelder.

After the Exxon Valdez tanker accident in 1990, Du Pont's oil-marketing subsidiary, Continental Oil Co., announced plans to build two crude-oil double-hull tankers to prevent oil spills.

Blackwelder said Du Pont's claim that the use of double-hulls was a pioneering step is misleading because one out of every six tankers carrying crude oil are double hulled. "In fact, double-hulls have been around for more than 20 years," Blackwelder said. "They say they are protecting the planet and cleaning up their act, but behind the scenes, it's pollution as usual," he told the press conference.

Doyle added that Du Pont has paid out nearly $1 million monthly from 1989 to June 1991 for environmental infractions -- the same time frame in which the company began promoting its environmental initiatives.