Toyota is grappling with plunging sales — down 39 percent so far this year — and idle production capacity in the United States that contributed to its $4.3 billion loss last year. Under the new structure, Yoshimi Inaba, a former U.S. sales chief who was recently rehired by Toyota, will be based in the United States and hold two traditionally separate jobs. He will be president of Toyota Motor North America, the New York-based regional holding company, as well as chairman of Toyota Motor Sales in Torrance, Calif., according to a company statement.

Inaba will report to Atsushi Niimi, an executive vice president based in Japan who once headed Toyota’s U.S. manufacturing operations.

Niimi will be in charge of the North America Operations Group as well as chairman of Toyota’s North American manufacturing and engineering subsidiary based in Erlanger, Ky.

The company said the organizational changes are designed to allow each region to take more initiative. At the same time, the management appointments seem aimed at helping Toyota’s top managers keep close tabs on the U.S. market, traditionally its most lucrative.

At his first news conference as president, Toyoda said Thursday in Tokyo that the U.S. auto market could evolve to comprise more smaller and more fuel-efficient vehicles. He said Toyota needed to increase its responsiveness to customer demand in each market.

Some company executives believe the automaker was unprepared for the sudden changes in the U.S. market after focusing too much on developing and selling large vehicles, said Masaki Taketani, analyst at CSM Worldwide. “They have to change,” he said.

Under the new system, the Americas Operations Group has been split, with the Central and South American business shifted to another unit including Middle East and Africa operations.

Within North America, Toyota Motor Sales President Jim Lentz will report to Inaba, who will be the highest ranking officer in the U.S. and will be based in New York. Tetsuo Agata remains president and CEO of Toyota Motor Engineering & Manufacturing North America in Kentucky.

Steve St. Angelo is appointed executive vice president of the U.S. manufacturing subsidiary and a managing officer of the parent company in Japan. St. Angelo remains president of Toyota’s Georgetown, Ky., assembly plant.

Toyota Motor Sales USA President Jim Lentz says his company shares about two-thirds of its 500 parts suppliers with GM, which is facing the possibility of a bankruptcy. Lentz made the remarks Wednesday at the New York International Auto Show.

Lentz says only a small number of Toyota suppliers are critically short on cash. Analysts fear that an automaker bankruptcy would take down parts suppliers and disrupt production industrywide.

Lentz says the $5 billion parts supplier bailout by the Obama administration will help preserve the supply base. The Tokyo-based automaker builds cars in the U.S. in Kentucky, Indiana and Texas.

Inaba will return to the United States, a Toyota spokesman at the company’s U.S. sales operations, said Friday. His title and responsibilities will be finalized in June, said Irv Miller, group vice president of environmental and public affairs at Toyota Motor Sales Inc. in Torrance, Calif.

Toyota recently rehired Inaba, who ran Toyota’s U.S. sales operation from 1999 to 2003. In his new position, Inaba is expected to lead a more streamlined U.S. operation, people familiar with the situation have said.

Yukitoshi Funo, now chairman and CEO of Toyota Motor Sales, will return to Japan in June with the title of executive vice president responsible for government and public affairs, overseas sales and projects.

Steve St. Angelo, president of Toyota Motor Manufacturing Kentucky, Toyota’s oldest plant in North America, will become a managing director of the company.

Toyota outlined the management moves in its annual list of board and executive appointments and retirements.

Earlier this year, Toyota announced that Akio Toyoda, the grandson of the company’s founder, will be appointed president, succeeding Katsuaki Watanabe.

The appointments hinge on the approval of shareholders, who will hold their annual meeting in June.

Among the officials retiring are Honorary Chairman Shoichiro Toyoda, the son of the founder, and former Toyota chairman and CEO Hiroshi Okuda.