UK network operator O2 has told ZDNet that it is aiming to get its 3G data service up and running again by Thursday afternoon.
A spokesman for the company said on Thursday morning that 3G connectivity should be restored some time in the afternoon for its mobile customers.
"We can't be more specific than that right now. We're working hard to restore services," he said.
The company suffered a major outage that began on Wednesday, leaving hundreds of thousands of its customers without access to voice, text or data services.
At 8am on Thursday, O2 said it had restored its 2G data services and advised customers to turn off 3G data in order to restore mobile voice services.