San Francisco

SLACK Technologies, a Silicon Valley darling that's raised more than US$300 million, wants to give some of that money back. The startup, which runs a popular corporate chat service, is forming an US$80 million venture fund to invest in other startups.

Stewart Butterfield, chief executive officer of Slack, said that his company is contributing more than half of the total fund. The rest will come from some of Slack's own backers. The fund will invest about US$100,000 to US$250,000 in smaller startups building applications that work with Slack's messaging service, Mr Butterfield said.