Telstra customers could experience a drop in mobile coverage while works to improve network capacity and mobile coverage are conducted in Warrnambool.
The works, which begin on Friday, are expected to be completed by February 21.
Telstra Victoria regional general manager Steve Tinker said it was upgrading the Warrnambool Telephone Exchange mobile base station.
"Residents may notice an intermittent or temporary reduction of mobile coverage while this upgrade is occurring," Mr Tinker said.
Customers were notified about the upgrade by text message on Wednesday and he apologised in advance for any inconvenience caused.
He said Telstra announced in February it would invest more than $160 million on 600 mobile network projects across Victoria this financial year, to help eliminate mobile black spots, improve data speeds and capacity.
"More than half of this investment is in regional areas, including a commitment to invest more than $20 million to complete 74 mobile network projects in and around Ballarat and south-west and Western Victoria."
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