The claims against Ford stemmed largely from Firestone tire failures, which U.S. safety regulators have linked to about 270 deaths, many in rollover accidents involving Ford's popular Explorer SUV.

The world's second-largest automaker denied any wrongdoing. But the $51.5 million nationwide settlement "resolves allegations of deceptive trade practices relating to the sales and advertising of Ford sport utility vehicles," Iowa Attorney General Tom Miller said in a statement.

Ford has already spent about $2 billion to replace millions of allegedly faulty tires produced by Bridgestone Corp.'s (5108.T) Firestone unit that were fitted as standard equipment on Explorers and other SUVs.

But Miller said the states' investigation focused on allegations that Ford continued to use certain Firestone tires even after the company knew the tires had had an unacceptably high failure rate that heightened the risk of dangerous rollovers.

The states also alleged that Ford's advertising misled consumers about the safe use of SUVs, which have a higher center of gravity than cars and are more prone to rollover accidents.

Additionally, according to statements from the attorneys general, they alleged that certain replacement tires, sold through Ford's "Around the Wheel" program, were falsely advertised as the same tires that came equipped on Ford SUVs.

CONSUMER EDUCATION

The states said they will use $30 million of the money from Ford to launch a national consumer education campaign on SUV safety. The remainder will cover legal costs, additional consumer education programs, and unspecified litigation going forward.

As part of the settlement, Ford will share its patented Belt-Minder technology - which rings a bell when passengers are not wearing seat belts - with other automakers.

The automaker will also add an advisory that says "Do Not Attempt" to ads showing its vehicles climbing up steep slopes or performing other risky maneuvers.

"For a multibillion-dollar corporation this is a slap on the wrist," said Clarence Ditlow, executive director of the Washington-based Center for Auto Safety.

"It does nothing for the rollover hazards of the Explorer, for consumers who own the Explorer," said Ditlow, who alleges that older model Explorers are still prone to high rates of rollover and roof crush.

Joan Claybrook of Public Citizen, another Washington-based consumer advocacy group, said the money from Ford - and from a similar $51.5 million settlement last year with Firestone - would be well-spent, however, if it was used by state governments to launch an effective SUV safety campaign.

"The public still is uninformed and misinformed about the safety of SUVs," Claybrook told Reuters.

"If they just tell people to drive more safely it's a waste of money," she added, saying automakers themselves should be forced into building vehicles that are safer and more stable than today's SUVs.