Twitter chief executive and co-founder Jack Dorsey has said he will give a third of his shares in the company to staff.

Mr Dorsey, who was re-appointed chief executive earlier this month, said he wanted to "reinvest directly in our people".

He owns 3% of the social media giant, and the 1% going to Twitter's staff is worth around $197 million (£128m). Dorsey tweeted: "I'd rather have a smaller part of something big than a bigger part of something small."

Last week, former Microsoft boss Steve Ballmer bought 4% of shares in Twitter, making him the largest individual shareholder.