ST. LOUIS (AP) - North Dakota and six other states aggressively bidding for a billion-dollar power plant prototype will learn next week which of the dozen sites contending for the so-called FutureGen advance as finalists.

A consortium that includes various coal and electric companies working with the Department of Energy in developing FutureGen will reveal Tuesday the handful of sites that will move on to further scrutiny, officials with the alliance told reporters Wednesday.

The winner will be tapped next year, five years before the virtually pollution-free plant is expected to be running.

The competition among states has been fierce, including hundreds of millions of dollars in enticements - everything from grants to low-interest loans and free land - in the hunt for more than 1,000 construction jobs and 150 permanent ones the FutureGen project would bring.

Ken Humphreys, a technical support manager for the alliance, said would-be host cities were scored on roughly 100 peer-reviewed, publicly vetted criteria, including their access to coal, water, rail lines, power transmission and underground geology that would allow permanent storage of carbon dioxide waste.

For sites to advance, "they have to meet and preferably excel against those criteria," Humphreys said during a media briefing by teleconference. "It is not politics, it is not just the companies and the alliance that are picking the site. It's driven by engineering, and it's driven by science."

Touted as the power plant of tomorrow, FutureGen involves technology that converts coal into highly enriched hydrogen gas that burns more cleanly than coal. Plans call for the 275-megawatt plant to capture most of its emissions of carbon dioxide - a "greenhouse" gas widely blamed for global warming - and inject them permanently into underground reservoirs, a process called sequestration.