TOKYO — Japanese automakers, including No. 1 Toyota Motor Corp., called production halts today at factories in Japan because of quake damage at a major parts supplier.

The temporary closure of auto parts maker Riken Corp.'s plant at Kashiwazaki city, near the epicenter of Monday's magnitude 6.8 quake, has forced Toyota, Nissan Motor Co. Mitsubishi Motors Corp. and Fuji Heavy Industries to scale back production.

Toyota, Japan's top automaker, will stop production lines at a dozen factories centered in central Aichi prefecture Thursday afternoon and all day Friday, said Toyota spokesman Paul Nolasco.

The company will assess the situation at Riken, supplier of key transmission and engine parts to Toyota, before deciding whether to resume production on Monday, he said.

Tom Libby, J.D. Power and Associates' senior director of industry analysis, said customers shouldn't notice the shutdown because Toyota likely has sufficient inventory to cover a few days of lost production.

"I don't think their inventory is that tight. I think they'll be able to adjust and probably make up for it afterwards," Libby said.

He said he was unsure of the impact if the shutdown lasts beyond the end of the week.

For now, it should have minimal impact on U.S. customers because Toyota has sufficient inventory on hand, said Mona Richard, a company spokeswoman in Detroit.