AT&T announced the CEO of its Communications business John Donovan would retire at the start of October, sparking wide speculation at the identity of his successor.

The industry veteran – informally regarded as AT&T’s number two exec – leaves after 11 years with the operator, where he previously held the roles of CTO, chief strategy officer and group president for technology and operations. Prior to joining AT&T, Donovan worked at internet security company Verisign, identity specialists Incode and Deloitte.

The operator is yet to unveil the identity of a successor, though US business media have speculated a number of internal candidates could be elevated to the role.

Among the names floated by Bloomberg are its Latin America CEO Lori Lee, and EVP of global connections and supply chain Susan Johnson. Indeed, reports suggest Donovan’s retirement could pave the way for a woman to ascend to the biggest role for a female executive in the company’s history. Other names in the frame include WarnerMedia CEO John Stankey and AT&T business CEO Thaddeus Arroyo.

The operator’s Communications division is the company’s largest and comprises its entire US mobile and fixed operation in addition to its business, technology and several entertainment assets. AT&T’s other divisions are WarnerMedia, Latin America and Xandr, which is focused on digital advertising.

AT&T chairman and CEO Randall Stephenson described Donovan as a tech visionary and credited him with leading the operator’s drive towards 5G, fibre and ongoing buildout of the US public safety network FirstNet.

He added: “He led the way in encouraging his team to continuously innovate and develop their skill sets for the future. We greatly appreciate his many contributions to our company’s success.”

In a statement, AT&T said it would announce a replacement “soon”.