Owner sells credits to commission, a developer or other buyer, but retains ownership minus development rights.

Under the deal announced today, Lilco would not sell credits to companies in 10 Southern and Midwestern states.

Certain sectors like steel benefited from over-allocations by selling excess credits.

Once approved by regulatory agencies the mitigation bank may sell credits to developers whose projects will impact these various ecosystems.

A utility that has aggressively reduced its emissions can sell or trade credits to a utility in any state that has not acted so quickly.

That will enable it to sell credits, defraying at least part of its investment.

Making money by selling credits was not the purpose of the program.

Several European countries had already set up a trading system to allow companies that reduce their emission levels below government targets to sell "credits" on an international market.

And they contain an innovative pollution-trading system that would allow clean utilities to sell "credits" to dirty ones.

Developing countries sold credits last year to richer nations for an average price of $10.70 each.