(Corrects to "26 cents" from "28 cents" in paragraph 3)
Sept 4 (Reuters) - Slack Technologies Inc, the workplace messaging and communication platform, posted a huge loss in its first quarter as a public company as it spent heavily on sales and marketing to boost engagement on its platform and retain users.
Shares of the company fell 6% in extended trading.
The company, described as an "email killer", said net loss attributable to common stockholders rose to $359.56 million, or 98 cents per share, in the second quarter ended July 31, from $31.86 million, or 26 cents per share, a year earlier. (Reporting by Arjun Panchadar in Bengaluru; Editing by Maju Samuel)