BATON ROUGE, La. — Entergy Corp.'s New Orleans utility filed for bankruptcy yesterday after its electricity and natural-gas systems sustained as much as $475 million in hurricane damage and thousands of its customers were left without power.

Entergy Corp., based in New Orleans, said earlier this week it was considering the filing along with seeking federal aid and insurance payments to cover the costs of storm damage to its electricity and natural-gas systems. The company said Hurricane Katrina caused roughly $1.1 billion in total damage, including the estimated $475 million to the New Orleans unit.

"They needed to spend money on restoration and apparently didn't get adequate assurance from officials that they'd be able to recover it," said Paul Clegg, a utility debt analyst for Natexis Bleichoeder in New York who doesn't own the stock and doesn't carry a rating on it.

"By making themselves the debtor-in-possession, Entergy makes sure they are first in line to be repaid."

Entergy New Orleans is the smallest of Entergy's five utility companies. It accounted for about 7 percent of the parent's revenue in 2004, the company said. The unit has served the New Orleans area for more than 80 years.

"We took this action after careful review of the various options available to preserve Entergy New Orleans' business over the near and long term," Dan Packer, the unit's chief executive, said in a statement.

Entergy Chief Executive Joe Domino said today the company's Gulf States utility has the resources to deal with Hurricane Rita and he doesn't anticipate any cash shortage.

Hurricane Rita was expected to come ashore early today near the Texas-Louisiana border as a Category 3 storm.

Entergy agreed to provide as much as $200 million in financing to its New Orleans unit to pay near-term expenses, including $36 million in payments due Monday under gas supply agreements, according to court filings. The financing needs court approval.

"It was a necessary move," said Barry Abramson, who helps manage $28 billion at Gabelli Asset Management in Rye, including fewer than 25,000 Entergy shares. "They have a massive rebuilding effort, but they don't yet know how many customers they will have."