Toyota Motor Corp. said Tuesday it will temporarily halt the sale of a Lexus sport-utility vehicle after Consumer Reports magazine raised safety concerns about it, The Wall Street Journal reported.

The move was another blow for the Japanese car maker, which is trying to repair its image after a series of safety recalls. Consumer Reports issued a rare "don't buy" recommendation for the Lexus GX 460, saying the SUV could roll over in certain situations.

The influential nonprofit magazine already had suspended its recommendations for eight Toyota models recalled in January for sticky-accelerator concerns. In certain conditions, the gas pedal in those models is slow to return to idle.

Recently, four of the magazine's auto engineers found a safety risk in the 2010 Lexus GX 460 SUV during their standard emergency-handling tests.

"On this vehicle, the tail will slide out quite abruptly," said Jake Fisher, a senior automotive engineer on the magazine's testing staff, in an interview. "During our testing it was basically perpendicular to the track and you're completely sideways."

In a real-world driving situation such as exiting a highway ramp, the condition could cause a serious rollover accident, Mr. Fisher said.

Lexus spokesman Bill Kwong said the company's engineers in the U.S. and Japan are working to reproduce the test quickly and hope to determine the cause by the end of the week.

In most Toyota vehicles, the stability-control system—a computerized setup that modulates the brakes and sometimes the throttle to prevent skids—won't let a driver end up in the situation created by the magazine's testers, Mr. Fisher said.

The National Highway Traffic Safety Administration, the agency that oversees vehicle testing, on Tuesday cautioned drivers of the Lexus "to avoid excessive speed and aggressive maneuvering in order to maintain control of their vehicles," according to an email from Julia Piscitelli, NHTSA's director of communications.

The agency is in the process of making sure the Lexus SUV complies with its safety standard for electronic-stability control. "It is our belief that [electronic stability control] should prevent the kind of fishtail event described," Ms. Piscitelli said.

Last week, U.S. Transportation Secretary Ray LaHood said he would seek a $16.4 million civil fine, the largest ever against a car maker, for Toyota's failure to quickly disclose potential safety defects as required by law. He added that NHTSA isn't done with its investigation into Toyota's safety problems.