(Reuters) - Slack Technologies Inc, the owner of the workplace instant messaging app, said here on Monday it had registered about 117 million of its Class A shares, which is an estimate for the number of shares that will be needed when the stock begins to trade.

Slack is the latest tech company looking to go public this year, following the market debuts of Uber Technologies Inc, Lyft Inc, Pinterest Inc, and Zoom Video Communications.

Slack has opted for direct listing instead of an IPO, which has been the traditional route to the public markets for companies like Google parent Alphabet and Facebook Inc.

Slack also changed its ticker symbol to “WORK” from “SK”.

(This May 20 story Corrects to drop reference to company raising $197 million in headline and paragraph one and $100 million in paragraph five.)