Isuzu Motors annual earnings jumped 57% to a record high but the truck and diesel engines specialist reportedly predicted that earnings would decline in the current fiscal year due to higher costs and weaker domestic sales.

The truck maker posted a group net profit for the year to the end of March of 92.39bn yen ($US700m; EUR569m), up from 58.96bn yen the previous year, The Associated Press (AP) reported.

Group revenue for last fiscal year rose 5.1% to 1.66 trillion yen from 1.58 trillion yen.

But for this fiscal year, Isuzu expects net profit to fall 13% to 80bn yen while sales are projected to slip 0.8% to 1.65 trillion yen, the report said.

Isuzu, which formed a capital alliance with Toyota Motor in November after dissolving its tie-up with General Motors in April 2006, reportedly said demand for trucks in Japan would likely fall this year as fewer new vehicles will be needed to meet stricter emissions guidelines.

AP noted the company is also expecting higher costs for materials and from the development of safety and fuel-efficient technologies.

Its global vehicle sales grew 4.9% to 468,301 units last fiscal year, as overseas sales climbed 6.7% to 371,500 vehicles. Domestic sales dropped 1.4% to 96,801 vehicles, the Associated Press reported.