AUSTIN—Many of the millions of Texans who lost power from Hurricane Ike’s wrath won’t get it back for weeks, as utility companies struggle to undo damage inflicted on high-voltage transmission lines, officials said Saturday.

Dottie Roark, spokeswoman for the Electric Reliability Council of Texas, which operates the power grid for most of the state, said two-thirds of the electricity transmission used by Houston-based Centerpoint Energy customers went down. That includes eight of the 345 kilovolt lines—the largest on the grid, she said.

“In some of these areas, it could be weeks before they get their power back on,” Roark said. “Two-thirds of the transmission—that’s a big hit.” Entergy, the electric utility, has also reported major damage to its transmission lines, company representatives said.

More than three million people in Southeast Texas were left without power after Hurricane Ike roared ashore. Terry Hadley, a spokesman for the Texas Public Utility Commission, said the fate of those high-voltage lines, the main arteries of the electric grid, will greatly affect how long people are without power.

“The key will be what damage there is to major transmission lines,” Hadley said. “The first priority is search and rescue. And then they’ll move in the power companies as soon as there’s an all clear.”

Hadley said the power outages in the Beaumont area is more extensive than the devastation left by Hurricane Rita in 2005. Hadley said crews from utility companies outside the affected areas would likely help with the restoration effort, which will likely begin on the western edges of the storm and move east toward the areas with the most damage.

“Just about everybody in the greater Houston area and Beaumont is without electricity unless there is back-up power,” Hadley added.

State officials are meeting in Austin to discuss emergency response efforts, including the restoration of electric power. Texas wasn’t the only state to see major power outages. Some 140,000 lost electricity in Louisiana. That’s in addition to the 60,000 still without power from Labor Day’s Hurricane Gustav.

The power outages only add to the uncertainty of evacuees about when they might be able to return home.

Jeffery Singletary, 33, fled from Houston with his wife and three young children and stayed with a relative in Tyler. “We will be here as long as the electricity is out in Houston,” he said. “If it’s two weeks, we’ll be here two weeks.”