Jun. 7--The New York investment firm that expects to soon take control of a critical Dane County power plant says it might be forced to shut it down, a move executives say could jeopardize the area's electricity supply during high- demand summer months.

But government regulators and a regional electricity consortium believe those fears are unfounded, noting that other options are available.

The CIT Group is awaiting federal approval to retake control of the RockGen Energy Center in the town of Christiana, which it had leased to the now-bankrupt Calpine Corp.

The power produced by Calpine at the plant -- designed to run only during high-demand times -- had been sold to Wisconsin Power & Light, Alliant Energy's local subsidiary under a long-term contract.

CIT Group had hoped to continue selling power to WPL under similar terms when it takes control of the plant, which could happen by mid- July.

But their asking price was too high, Alliant spokesman Scott Smith said, and the company is evaluating bids from other sources for the balance of the contract from 2007-09.

The utility provider is in final talks for a stopgap solution for this summer, Smith said.

If Alliant looks elsewhere for power, it would leave the plant without a customer, said Dan Morash, the managing director of CIT Group's structured finance unit.

"We'll have no choice but to shut the plant down," Morash said. "It'd be uneconomic to operate."

But even if the plant, about 20 miles east of Madison, were shut down, the consequences would not be catastrophic, according to both the state Public Service Commission and the Midwestern Independent Service Operator, the manager of the region's power supply grid.

"With or without RockGen, the commission is confident that we'll meet our reserve requirements," PSC spokeswoman Linda Barth said.

Wisconsin utilities are required to maintain an 18- percent reserve supply of available electricity at all times.

Alliant officials have testified in the past that RockGen's locally produced power is necessary because it's cheaper and more reliable than electricity imported from other states.

Morash said continuing that arrangement is in the best interest of ratepayers.

But the transmission system has improved since then, said MISO spokesman Gary Rasp.

"If the plant were not available, it would not cause a reliability issue," Rasp said. "That's based on our recent summer assessment projections."

Mark Williamson, vice president of American Transmission Co., wasn't so sure, saying that theoretical projections don't always consider the day-to-day concerns of ATC's operators.

"If that plant goes down, it gives us no flexibility to handle other problems that come up," he said.