Twitter COO Adam Bain Is Leaving After 6 Years Building the Company’s Ad Business

Anthony Noto replaces him

Adam Bain, a Twitter exec since 2010, is leaving the company. He served as COO for the past year and a half, after serving as the microblogging platform's revenue chief for half a decade. 

"I'm grateful to Adam for everything he's done for Twitter, and for his leadership and friendship over the years," said Jack Dorsey, Twitter's CEO, in a statement. "I can't wait to see what he does next!"

Bain's post-Twitter plans were not revealed.

Anthony Noto, who has served as the company's chief financial officer since July 2014, is replacing Bain as COO. Twitter will now look for Noto's replacement. 

It's a surprising development, as Bain has been considered a key executive when it comes to the social media company's relationships with ad agencies and media partners. Last year, Bain was thought to have an outside shot at being Twitter's CEO, but that role ultimately went to Dorsey, who returned to the company he helped found.