Hours after AT&T's advanced advertising unit, Xandr, announced that it will make the linear TV inventories of Disney and AMC Networks, as well as AT&T's WarnerMedia, unnamed Reuters sources reported that Xandr CEO Brian Lesser had resigned.
AT&T declined to comment and Lesser was not immediately reachable by Reuters.
Lesser, who joined Xandr in 2017 from GroupM, where he was most recently heading up North American business, originally reported to AT&T CEO Randall Stephenson. He began reporting to John Stankey last September, when Stankey became president and chief operating officer of AT&T.
Stankey has also continued as CEO of WarnerMedia, but the company is seeking a successor for that role and has reportedly considered Randy Freer, Hulu's former CEO, and Jason Kilar, Hulu's founding CEO, as candidates.
Lesser interviewed for the WarnerMedia CEO position but had "received an indication that he would not be selected," according to Reuters.
A Reuters source claimed that Lesser "felt comfortable resigning now because Xandr's in good shape and Q1 results should show significant growth." Xandr's revenue increased 15%, to $2 billion, last year, according to AT&T.
However, other reports note that AT&T may have been disappointed with the speed of the Xandr's revenue ramp-up.
In his push to make Xandr a data-driven marketplace offering ad buys across linear and addressable TV, OTT streaming services and digital video, Lesser last year made a $1.2-billion deal to acquire AppNexus --the DSP that was rebranded as Xandr Invest -- followed by the acquisition of sell-side platform Clypd.
In addition, some buyers have said that the alignment between Xandr's and WarnerMedia's strategy lacks clarity.
Xandr and WarnerMedia are set to present a joint Upfront for the first time. WarnerMedia has yet to replace Donna Speciale, who left her role as president of ad sales last July.