AUGUSTA – With winter approaching and power demands rising, utility and state officials reminded Mainers on Monday that they may be asked to cut back on energy use in the weeks ahead in order to avoid rolling blackouts.

Officials said conservation advisories could be issued if the region experiences a cold snap; rolling blackouts would be ordered only as a last resort.

“Weather and fuel conditions would have to be extreme for this to happen,” said Stephen Whitley, chief executive officer of ISO New England, which manages the region’s power grid from its headquarters in Holyoke, Mass.

Damage by Hurricanes Katrina and Rita reduced supplies of natural gas used in the region’s power plants. In response, ISO has taken steps to stretch available energy supplies, such as modifying generators to run on oil as well as gas, Whitley said.

Consumers also could be asked to do their part in the event electricity demand increases sharply due to a stretch of bitterly cold temperatures or if supplies drop because of problems at a power-generating station, or both, he said.

First, there would be a “power watch” in which New England consumers would be asked to voluntarily cut back on electricity use.

If the situation worsened, creating a concern power companies would have to disconnect customers to reduce demand, a more urgent “power warning” would be issued. In that event, consumers would be asked to turn off all unnecessary lights and office equipment, delay doing laundry and running dishwashers until after 8 p.m., turn off space heaters, and limit cooking and bathing until past 8 p.m.

Gov. John Baldacci and his counterparts from the other five New England states have agreed to issue power warnings if asked, said Whitley, who spoke at a news conference with state officials and utility regulators at Maine Emergency Management Agency headquarters.

Only dire circumstances would necessitate what grid operators classify as “Operation 7,” or rolling blackouts, which would ripple throughout the six-state region.

While such a scenario is unlikely, “We have an obligation to plan for contingencies,” said Kurt Adams, chairman of the state Public Utilities Commission.

Adams said power warnings can be effective in reducing demand on the region’s power grid, which typically experiences a peak demand in winter of 17,000 to 19,000 megawatts a day. “Four-hundred megawatts [in savings] from consumers is eminently achievable,” he said.