SAN FRANCISCO (AP) — California's largest greenhouse gas emitters will begin buying permits in a landmark "cap-and-trade" system designed to control emissions of heat-trapping gases and to spur investment in clean technologies.

The program is the most wide-ranging of its kind in the nation and a key part of California's 2006 climate-change law, AB32. The regulations dictate standards for cleaner-burning fuels, more efficient automobiles and increased use of renewable energy.

For the first time, the California Air Resources Board will auction off pollution permits on Wednesday called "allowances" to hundreds of businesses, including electric companies and refineries.

Some of the businesses regulated under California's plan say the extra costs will result in higher electricity rates and job losses.