Navistar International in January will lay off another 250 workers at its Springfield, Ohio, medium-duty truck plant due to slowing demand, a company spokesman told Reuters.

The total number of trucks and school bus chassis produced daily at the plant will drop to 143 from 162 currently, spokesman Roy Wiley said, according to Reuters. After the job cuts in early January, Navistar will employ about 1,750 workers at the Springfield plant, Wiley added.

Reuters said that three debt ratings agencies last week downgraded their ratings on Navistar's corporate credit, citing the weak truck demand, magnitude of restructuring costs and the postponement of a deal to supply diesel engines to Ford.

Navistar posted a net loss of $US536 million in 2002, its worst yearly performance in a decade, as freight haulers remained reluctant to place orders for new trucks in a soft US economy, Reuters noted.

The news agency said the company earlier this year cut approximately 800 jobs at the Springfield truck plant after it shut down one of its two production lines. It also shed about 650 jobs at a separate body plant in Springfield that was shuttered and 600 jobs at an engine plant in Indianapolis, Reuters added.