TOKYO » Toyota Motor Corp. said Wednesday it is recalling about 550,000 vehicles worldwide — mostly in the United States — for problems that could make it harder to steer.

The recall affects 447,000 vehicles in North America, as well as 38,000 in Japan and another 25,000 in Australia and New Zealand, said Toyota spokesman Dion Corbett. In Europe some 14,000 vehicles are being recalled along with 10,000 in the Middle East and 14,000 in Asia outside Japan.

Toyota has received a total of 79 reports about the defect dating back to 2007, said Corbett. There have been no reports of accidents or injuries related to the problems, he said.

Toyota’s reputation has taken a hit over the last two years due to a string of huge recalls that have ballooned to 14 million vehicles over that time, including millions recalled last year for acceleration problems. It faces damage lawsuits and lingering doubts in the U.S. about whether it had been transparent enough about the recall woes.

Japan’s largest automaker has been trying to communicate better with customers and empower regional operations outside Japan to make safety decisions.

The news comes a day after Toyota said its July-September profit slid 18.5 percent to 80.4 billion yen ($1 billion) on plunging sales caused by parts shortages from the tsunami disaster in northeastern Japan.

It now faces such uncertainties from flooding in Thailand, where it has many suppliers and three assembly plants, that it declined to release an earnings forecast for the full year through March.

The latest recall is due to the possibility that the outer ring of the engine’s crankshaft pulley may become misaligned with the inner ring, causing noise or a warning signal to light up, the company’s U.S. sales unit said in a press release. If the problem isn’t corrected, the belt for the power steering pump may become detached from the pulley, making it suddenly more difficult to turn the steering wheel.

In the United States, the automaker is recalling 283,200 Toyota brand cars, including the 2004 and 2005 Camry, Highlander, Sienna and Solara, the 2004 Avalon and the 2006 Highlander HV. Its recall of 137,000 Lexus vehicles includes the 2004 and 2005 ES330 and RX330 and 2006 RX400h.

Those affected elsewhere include certain models of the Alphard, Highlander, Highlander hybrid and some Lexus models, Corbett said.

The recall notification process varies from country to country.

In the U.S., Toyota will mail owners a notification to make an appointment with an authorized dealer to have their car inspected once replacement parts have been produced in sufficient quantities.

If needed, parts will be replaced for no charge, the company’s American sales unit said. Notifications will be mailed starting in January.

In the meantime, if an abnormal noise is heard coming from the engine compartment, the owner is asked to make an appointment with any Toyota or Lexus dealer to have the vehicle inspected for this condition, the release said.