The purchase, which Convergys said does not need regulatory nods because AT&T already controls the operations, comes at a time when the wireless carrier is in a battle with regulators and competitors to gain support for its proposed $39 billion deal with T-Mobile USA.
Convergys, which announced the deal on Thursday, holds a 34 percent stake in Cincinnati SMSA and a 45 percent limited-partnership interest in Cincinnati SMSA Tower Holdings, both of which it got when it spun-off from Cincinnati Bell
Cincinnati SMSA is a wireless communications provider, while Cincinnati SMSA Tower Holdings is a cellular tower holding company for Cincinnati SMSA.
The sale of the two wireless operations in the Cincinnati area is expected to generate net after-tax proceeds of about $250 million for Convergys, which expects to close the sale early next month.
AT&T expects impacts on profit and cash flow from the purchase to be insignificant.
Convergys shares closed at $12.55 on Thursday on the New York Stock Exchange while AT&T shares closed at $30.97.
(Reporting by Saqib Iqbal Ahmed, Abhiram Nandakumar; Editing by Joyjeet Das and Robert MacMillan)