The state Insurance Department is expecting Saturday’s October snow storm, which took down trees and power lines across the state leaving more than 955,000 utility customers without power, to be far more costly than Tropical Storm Irene.

Insurance Commissioner Thomas B. Leonardi said preliminary estimates expect the storm to cost between $1 billion and $3 billion, all told. Connecticut might make up more than 30 percent of that figure, he said. Asked to guess at what the total might come to, Leonardi put the damage in Connecticut somewhere around $500 million.

By comparison, he said so far claims related to Tropical Storm Irene have totaled about $150 million. That number will likely rise as more claims are processed, but he noted that much of the damage done during the August storm was flood damage, not covered under most insurance policies.

“This is looking really tough, even in comparison to Irene. It looks much worse,” he said in a Wednesday phone interview.

Leonardi stressed that it is too soon to know for sure what the storm will end up costing. Conditions on the ground in the state have hardly been conducive to quick and easy access for insurance adjusters to assess claims.

“As you know, being in Connecticut, people can’t easily get places right now,” he said of the downed trees and wires that still block many secondary roads.

It will be a week or more before the department has a better idea of the scope of the price tag associated with the storm’s damage, he said. Leonardi said the department has taken steps to ensure insurance claims can be processed as soon as possible.

On Tuesday he announced he renewed the licenses of the out-of-state emergency adjusters licensed to deal with claims in the aftermath of Tropical Storm Irene for an additional 90-day period to help with the snow storm. More than 5,600 out-of-state adjusters have been licensed since Irene and the department is currently processing more emergency requests from insurers, he said.

“This was done as a precaution to ensure there were no impediments to insurance companies quickly processing claims,” he said.

The department has also launched a special web site to assist policyholder with Internet access with the claims process associated with the storm damage. The site includes claims phone numbers for insurance providers, tips for making claims, frequently asked questions for dealing with downed trees and assessing spoiling food, as well as information on emergency licensing for insurers.