NEW YORK (AP) -- Twitter's chief operating officer, Ali Rowghani, has resigned from his post and won't be replaced as CEO Dick Costolo seeks more direct involvement with the company's engineering and product teams.
Rowghani joined Twitter in 2010 as chief financial officer and became COO two years later. Before that, he served as CFO at Pixar Animation Studios for nine years.
Twitter Inc. said in regulatory filing Thursday that Rowghani's responsibilities will be shifted to other executives. It did not give a reason for his departure. With the shift, Twitter joins other tech companies such as Google, Yahoo, Apple and Netflix that do not have a COO. Facebook's Sheryl Sandberg is a notable exception.
Rowghani had been tasked with expanding Twitter's user base, but this has not happened as quickly as investors had hoped. The San Francisco-based social media company has been trying to broaden its reach, most recently by luring in World Cup fans who want to follow teams and players using its service.
Rowghani's departure comes less than two weeks after Christopher Fry, Twitter's senior vice president of engineering, resigned and took on an advisory role. He was replaced by Alexander Roetter, who'd been Twitter's vice president of engineering.
Twitter's shares climbed $1.45, or 4.1 percent, to $37 in morning trading following the announcement. The stock has traded in the range of $29.51 to $74.73 since Twitter's initial public offering in November.
On his Twitter account, which is followed by some 22,700 people, Rowghani posted "Goodbye Twitter. It's been an amazing ride, and I will cherish the memories."