NEW YORK Reuters ATT Inc, the secondbiggest U.S. wireless carrier, is exploring a sale of its cybersecurity division, potentially undoing an acquisition it completed five years ago, according to people familiar with the matter.

The sale of the cybersecurity business would add to a string of divestments ATT has turned to in order to pay down debt following its 108.7 billion acquisition of Time Warner Inc in 2018, a deal it has since also unwound.

In the last two years, ATT sold a 30 stake in its pay TV unit DirecTV to private equity firm TPG for 1.8 billion, and received 40.4 billion in cash by spinning off and merging its Warner Media business with Discovery Communications to form Warner Bros Discovery Inc.

ATT has been working with Barclays Plc to solicit potential bids for its cybersecurity business, which was called Alienvault when it was acquired in 2018 in a roughly 600 million deal, the sources said. It is not clear how much the business could fetch now.

The sources cautioned that no deal is certain and requested anonymity because the matter is confidential. ATT and Barclays declined to comment.

ATT39;s cybersecurity division helps smalltomediumsized businesses keep their information technology networks, including laptops, desktops, servers and mobile devices, secure.

The acquisition of Alienvault was aimed at giving ATT an edge in signing up and retaining corporate clients, but the deal39;s rationale has eroded as cybersecurity startups that offer cheap…