Influential nonprofit magazine Consumer Reports on Tuesday urged car shoppers not to buy the 2010 Lexus GX 460, calling the Toyota Motor Corp <7203.T> sport utility vehicle a safety risk to roll over.

The magazine, which is seen as an objective voice on auto safety and quality in the North American market, said the 2010 Lexus GX 460 was prone to slide when driven in sweeping turns and gave the vehicle a not acceptable rating.

The rare safety warning comes at a time when Toyota is battling to repair damage to its reputation from a punishing series of recalls.

Toyota said in a statement that it was concerned with the Consumer Reports warning about the performance of its stability control system and would try to duplicate its test result to determine if appropriate steps need to be taken.

We take the Consumer Reports' test results seriously, the automaker said.

The last time Consumer Reports concluded that a vehicle was not acceptable for consumers to buy was in 2001, when it warned consumers away from the Mitsubishi Montero Limited.

The warning also stands out because past endorsements from Consumer Reports have been credited as one reason for Toyota's steady sales growth in the United States over the past 15 years.

IHS Global Insight analyst Aaron Bragman said the Consumer Reports finding was indicative of Toyota's troubles overall and the damage the company and the brand's reputation.

It certainly does no favors for Toyota and adds doubts in peoples minds as to the safety and reliability of Toyota vehicles, Bragman said.

Toyota has struggled under massive recalls due to defective sticky accelerator pedals and the potential for floormats to entrap the accelerator. The sticky accelerator pedals also led to U.S. sales and production halts.

ANOTHER CHINK IN TOYOTA ARMOR

U.S. safety regulators have proposed a record $16.4 million fine against Toyota, the highest allowed, accusing the automaker of knowingly delaying a recall over the defective accelerator pedals and may seek more penalties. The recalls also sparked congressional hearings and numerous lawsuits.

The automaker's U.S. sales fell 16 percent year-over-year in January and 9 percent in February before rising 41 percent in March under unprecedented incentives. Toyota has extended broad incentives and widened a maintenance offer into May.

Investigations continue into whether unintended acceleration, which Toyota has attributed to mechanical issues, also could have been caused by electronics issues.

Dennis Virag, president of the Automotive Consulting Group, said Toyota appears to have work to do on its software strategy to manage situations within the vehicle under normal or panicked driving situations.

It is another chink in their armor and an indication that perhaps they do have software problems not only in this vehicle but in other vehicles as well, Virag said.

Consumer Reports said the sliding its test drivers found in the GX 460 could cause rollover accidents resulting in serious injury or death. It said it knew of no reports of such accidents.

CR is urging consumers not to buy the GX 460 until the problem has been fixed, the magazine said in a statement.

Toyota has sold about 5,400 of the Lexus GX 460 SUVs in the four months since it has been on the market. The luxury SUV, which is based on the same platform as the Toyota 4Runner, starts at just over $50,000.

Consumer Reports said the vehicle's electronic stability control did not intervene quickly enough to stop the vehicle from sliding out in a turn. When pushed to its limits, the rear slid out almost sideways before it regained control.

The magazine said the risk of a rollover accident in the GX 460 was significant because it is a tall SUV with a high center of gravity.

It said no other SUV had slid as far as the Lexus in its recent testing, including the Toyota 4Runner.

(Additional reporting by Chang-Ran Kim in Tokyo; Editing by Sharon Lindores and Derek Caney)

Toyota Safety