Over the last year, state agencies have accumulated millions of dollars in so-called pollution credits.

Clear Skies was to use a market based system by allowing energy companies to buy and trade pollution credits.

Another major difference is that the federal plan allows generators to trade pollution credits, while New York's does not.

Because there have been few sales nationwide and little information about them, it is impossible to determine who is buying pollution credits.

The price for pollution credits, advocates hope, will be determined by trading among hundreds of buyers and sellers.

The pollution credits will help offset the cost of installing equipment in power plants in the those states.

That plant could then sell the 10,000-ton difference as a pollution credit to a new plant in Utah.

Some bill round-ups have focused on specific issues, like one last summer to buy and retire pollution credits.

It is also hoped that the program, if pollution credits are eventually granted, will attract other companies to voluntarily reduce pollutants.

He opposed pollution credits and giveaways of publicly owned assets.