The messaging platform company didn't provide details of its plans in a statement Monday.
Slack plans to forgo a traditional initial public offering and instead intends to sell its shares to bidders in a direct listing, a person familiar with the matter said last month.
The company is choosing the unusual method for going public because it doesn't need the cash or publicity of an IPO, the person said at the time.
The share sale, which might take place toward mid-year, could value Slack at more than $7bn (about R94bn), according to the person, who added that the San Francisco-based company's plans could still change.
The company was valued at $7.1bn (about R95bn) in a $427m (about R5.7bn) funding round in August.
If Slack goes ahead with a direct listing, it will follow music streaming service Spotify Technology SA, which began trading in New York using that method in April.
In an IPO, underwriters hammer out the number of shares to sell and at what price, and then take their fees out of the proceeds from an offering. A direct listing allows current investors to offer their stakes directly to new shareholders priced purely on demand.
