Ford Motor Co tumbled 10 spots in a widely watched reliability study due to problems with the new touch-screen entertainment system in some of its models and transmission issues in two of its most popular cars.

The second-largest U.S. automaker fell to No. 20 from tenth place a year ago, according to Consumer Reports' annual survey on reliability released on Tuesday, after its new Explorer SUV, Fiesta subcompact and Focus compact scored below average.

Japanese brands took the top nine spots on the list, led by Toyota Motor Co's <7203.T> youth-oriented Scion brand. The Toyota brand finished at No. 6, the same as in 2010.

Automakers compete hard for placement on the magazine's annual list of recommended models. The survey is seen as a factor in influencing the decisions of American car shoppers.

General Motors Co's four brands ranked in the bottom half of the list. But Chrysler Group LLC's Jeep brand vaulted seven spots to No. 13, making it the most reliable brand made by a U.S. automaker.

South Korea's Hyundai Motor Co <005380.KS> and Germany's Volkswagen AG , both making sales gains this year, held their spots at No. 11 and No. 16, respectively.

Consumers complained about Ford's new technologies, such as its entertainment system, known as MyFord Touch, and the automated-manual transmission used in the Fiesta and Focus.

First-year blues as Ford rolls out the new systems played a role in its dropping the most of any major automaker in the study this year, David Champion, senior director of Consumer Reports' Automotive Test Center, said in an interview.

For a major manufacturer to drop that far, it is concerning, Champion said.

(Reporting by Deepa Seetharaman; Editing by Gary Hill)