BANGOR – Almost half of the state’s Internet service providers lost access to the Web – and so did thousands of residential and business customers – when the providers’ wholesale Web connection went offline because of an unidentified disruption Tuesday night.

At least 24 of the state’s 52 Internet service providers rely on UUNet, a division of MCI WorldCom, to gain access to the World Wide Web.

Those service providers, and as many as 100,000 residential and business customers statewide, may not be the only ones impacted because the outage occurred in Massachusetts.

“There was a service disruption last evening [Tuesday] in the Boston ara,” said Janet Brumfield, a UUNet spokeswoman. “It happened after business hours and was restored last evening [Tuesday].”

Brumfield would not say how many Internet service providers in how many states were affected by the disruption.

“I don’t have that information and I don’t give that out,” Brumfield said. “There was nothing special about it and it’s been corrected.”

A spokesman for Bangor-based Prexar, an Internet service provider with more than 14,000 customers that was impacted by the outage, said based on his company’s computer readings the disruption lasted 11 hours. Some customers, but not all, could be re-routed to another wholesale Web connection, he said.

Prexar spokesman John McCatherin said Wednesday that his company’s connection to the Web went out at 4 p.m. Tuesday and did not return until 3 a.m. Wednesday.

Prexar tried to get answers from UUNet to explain what was happening to customers who were calling, but none were forthcoming, McCatherin said.

“We didn’t have any answers” for customers, he said.

On Wednesday night, Prexar still hadn’t received what Brumfield called a “confidential postmortem report” on why there was a service disruption, even though UUNet said one was sent out as a matter of routine.

“I checked with our network director and he has not received anything,” McCatherin said Wednesday night.

“He is our connection to them.”

Brumfield, however, said UUNet sent out the notices.

“My understanding is that [notification process] has been completed,” she said.