Twitter COO Ali Rowghani Leaving Company

UPDATED: The social-media company's head of North America media, Chloe Sladden, also announced plans to leave.

Twitter COO Ali Rowghani is leaving the social media company.

He tweeted on Thursday morning:

Rowghani resigns after joining the company as CFO in 2010 and becoming COO in 2012. Previously he was chief financial officer at Pixar. 

The company said in a regulatory filing that it does not plan to hire a replacement. The filing reads: "Mr. Rowghani will continue to be a Twitter employee and act as a strategic advisor to the CEO. Twitter does not intend to hire a replacement for the COO role, and all of Mr. Rowghani’s operating responsibilities will be assumed by other members of the Twitter management team."

Twitter CEO Dick Costolo tweeted back to Rowghani on his announcement:

His departure comes a day after Recode reported that Twitter has been restructuring its top management positions, removing the product department out from under Rowghani's purview and instead having vp product Daniel Graf report directly to Costolo. The report indicates that the move was the result of lackluster growth and product innovation at the social network. 

Rowghani had also come under fire for selling 300,000 Twitter shares, netting $9.9 million in profits, in May, despite the stock's downward slide. According to Recode, Costolo and Twitter founders Jack Dorsey and Evan Williams had vowed not to sell to signal confidence about the stock's long-term prospects. 

Rowghani was widely praised for his success in taking Twitter public in 2013. He was also instrumental in the deal to acquire Bluefin Labs, the TV analytics company, which led to Twitter's partnership with Nielsen to measure social ratings. 

Also departing on Thursday was Twitter's head of North America media Chloe Sladden, who announced her exit in a series of tweets.