[SAN FRANCISCO] Slack Technologies, whose software helps people collaborate at work, is in talks with investors to raise financing at a valuation of more than US$2 billion, according to people with knowledge of the matter.
The funding round hasn't yet closed, and the size and terms of the deal may change, said the people, who asked not to be identified because the talks are private. A representative of the San Francisco-based company declined to comment.
In October, Slack raised US$120 million in a round of financing co-led by Kleiner Perkins Caufield & Byers and Google Ventures, valuing the company at US$1.12 billion.
The investments are a further validation for Stewart Butterfield, who co-founded Tiny Speck and raised US$17 million to develop an online game called Glitch. Tiny Speck had US$5 million left when in 2012 Butterfield and the founders decided to shut down the game and return cash to stakeholders. Instead, their investors encouraged them to keep the money and start a new business, which became Slack. Mr Butterfield had previously sold photo-sharing website Flickr to Yahoo!in 2005.
More than 50 US technology companies reached a valuation of at least US$1 billion in the past two years, according to CB Insights. Other startups such as Airbnb and Snapchat have surpassed a US$10 billion valuation, while Uber Technologies has reached US$40 billion, the highest for a US startup.
Slack, which is based on Glitch's messaging and communication technology, said last month it had more than 500,000 active daily users. Last year, Mr Butterfield said companies such as Airbnb, EBay and Salesforce.com were using the product. Subscriptions cost US$8 a month or US$80 a year, he said at the time.
Slack, which has also raised financing from firms including Accel Partners and Andreessen Horowitz, was planning to double its head count this year from 63 last year, Mr Butterfield said.