Twitter has raised $200m (£129m) in new finance, in a deal that values the social networking service at $3.7bn.
It said the investment had come from venture capital firm Kleiner Perkins Caufield Byers, and existing investors.
Twitter is also adding two new board members, including David Rosenblatt, boss of digital advertising group DoubleClick.
The moves come two months after the US firm said it was increasing efforts to make itself more profitable.
The announcement in October saw the company's co-founder Evan Williams stand down as chief executive to focus on product strategy.
Mr Williams was replaced as chief executive by Dick Costolo.
Also now joining Twitter's board is Mike McCue, chief executive of digital social magazine application FlipBoard.
Twitter allows users to send 140-character text messages, or Tweets.
It has 175 million registered users and 300 employees.