Twitter's chief operating officer Adam Bain is leaving the social network, the company has announced.

The social network made the announcement in a regulatory filing, and Mr Bain confirmed it shortly afterwards on his Twitter feed.

“So...I have some news,” he wrote. “After six years and a once-in-a-lifetime run, I let Jack (Dorsey)know that I am ready to change gears and do something new outside the company.”

He said he felt he could leave the company in a place of strength. Chief financial officer Anthony Noto will take over as COO.

His loss will come as a blow to the firm. Mr Bain is credited with building Twitter's revenue, building it from practically nothing to billions of dollars, and was touted as a possible candidate for chief executive before cofounder Jack Dorsey took over on a permanent basis.

“I came here to help build out the business, but more importantly build a team. My team is the best legacy anyone can leave,” he said. “We took the company from $0 to Billions faster than almost anyone’s ever done it. We diversified the business, took it global.We took an organisation and scaled it in every way possible. Most importantly, we did it right - in the right way - in a way that makes us proud.”

He said he was planning to do something totally different and new outside the company.

Twitter announced last month it would cut 9 per cent of its global workforce, shedding as much as 350 jobs as it seeks to cut costs. The cuts are set to hit the firm’s sales, partnerships and marketing divisions. The company also said it would shut its Vine video service.

It recently hired bankers as it explored potential acquisitions, but failed to attract bidders.

The shuffle in the boardroom will take effect immediately, but Mr Bain will stay on in the coming weeks to assist with the transition.

“As has been my call for the entire six years: Go make history!” he said.