The attorneys general of 40 US states and territories on Wednesday sent a letter to 16 major vehicle makers warning that some advertisements featuring sport utility vehicles deceive consumers into believing that SUVs handle like cars, Reuters reported.

The letter said that vehicle industry ads could be considered "unfair and deceptive trade practices," which would be subject to future civil lawsuits, Reuters said.

The news agency reported that the letter said the vehicle industry has "blurred" the distinction between cars and SUVs in advertisements "which now trumpet the 'car-like' attributes of SUVs," and cited federal safety statistics which show that SUVs are three times more likely to roll over than cars.

Reuters said sales of SUVs have been growing steadily, fuelling vehicle industry profits, particularly the US makers, despite a growing number of attacks about the safety and environmental impact of the popular vehicles.

The warning comes as US safety regulators on Wednesday released road fatality rates for last year, which showed that the number of deaths resulting from rollovers of SUVs and pickup trucks rose by 4.9 percent to 10,626, or about a quarter of all road fatalities, Reuters said.

According to the news agency, the letter said the vehicle industry deceptively touts the cargo capacity of SUVs without mentioning safe weight limitations of the vehicles. Overloading is a significant factor in the SUV rollover accidents, the letter reportedly said.

Some ads also exaggerate the handling of SUVs by showing them perform high-speed manoeuvres, the letter said, according to Reuters.

A General Motors spokesman took exception to the accusations, Reuters said.

"The bottom line is we do not depict unsafe driving conditions in any of our advertising," GM spokesman Jay Cooney told Reuters. "A Silverado pickup is not a Corvette and our ads simply don't depict a pickup truck behaving like a sports car."

According to Reuters, the states said that many of the issues were addressed when all 50 states settled their deceptive advertising investigation of Ford and its SUV ads. After a two-and-a-half year investigation, Ford agreed to pay $51.5 million and change their advertising practices, Reuters noted.