CenturyLink shares (CTL) recovered after falling as much as 8.1%, to close down 4.6% at $25.72.
The employee claimed she lost her job after notifying CEO Glen Post about the company’s sales practices, that charged customers for accounts they had not requested.
Shares of Level 3 Communications (LVLT), to be bought by CenturyLink for about $24 billion, also fell by about 3%.
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The complaint alleges CenturyLink “allowed persons who had a personal incentive to add services or lines to customer accounts to falsely indicate on the CenturyLink system the approval by a customer of new lines or services,” according to the report which cited a lawsuit filed in Arizona state superior court.
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The company was not aware of the issue until the lawsuit had been filed, and was investigating the matter, CenturyLink spokesman Mark Molzen said.
A spokeswoman for Level 3 declined to comment.