A major initiative headed by the US Environmental Protection Agency (EPA) will see the firm Caterpillar embark upon a major program of reducing emissions.

The EPA has announced it is spearheading the 'Clean School Bus USA initiative', which it says will seek federal funding to pursue a nationwide upgrade of all school bus engines with the latest emission reduction technology.

Marking the launch of the EPA's program Caterpillar vice president Sherril West said the EPA program would help school districts and school bus fleet operators to either replace older buses with newer models or install low emission control devices on existing buses.

'We have invested heavily in technology that not only provides clean diesel engines for the future, but substantially reduces emissions from existing engines,' explained West.

The contract to refit America's school buses follows on from previous projects in similar areas, which the company says has seen a reduction of on-highway diesel emissions in trucks and buses by nearly 90 percent since 1988.