Twitter has raised a big new round of venture capital, $200 million, valuing the company at $3.7 billion.
The financing brings the total raised by the three-year-old company to $360 million. It was last valued at $1 billion when it raised money in September 2009.
A new investor, Kleiner Perkins Caufield & Byers, contributed $150 million, and existing investors, which include Union Square Ventures, Benchmark Capital and Spark Capital, invested $50 million.
The fresh capital comes as Twitter tries to prove that in addition to being an Internet phenomenon with 175 million registered users, it can also be a serious business. It has recently introduced several types of advertisements, courted big businesses and promoted Dick Costolo, its business-minded former chief operating officer, to chief executive.
In an unusual move, a Kleiner Perkins partner did not join Twitter’s board, but the company did add two new board members: Mike McCue, a co-founder of TellMe and current chief executive of Flipboard, which transforms Twitter feeds into a more attractive format; and David Rosenblatt, former chief executive of DoubleClick, the advertising company now owned by Google.
The Twitter investment is a big win for Kleiner Perkins, a firm that made its name in the 1990s investing in Web companies like Google and Amazon.com, but was late to get into the social networking trend. Recently, it has been trying to join in, with investments in companies like the game maker Zynga and a new fund for social networking start-ups.
“As part of the Twitter team, we look forward to helping build the next great Internet treasure,” Kleiner Perkins said in a statement.
News of the investment was first reported by the blog All Things D. Matt Graves, a Twitter spokesman, confirmed the details, and Mr. Costolo wrote about the funding in a company blog post.