Salesforce.com Inc. Chief Executive Marc Benioffs effort to buy Slack Technologies Inc., which is valued at $17 billion and would be his biggest acquisition yet, positions the company to take on Microsoft Corp. in key areas.
Salesforce has thrived for years as a niche business-software vendor. Now, the company is in advanced talks to buy Slack, The Wall Street Journal reported on Wednesday. The potential tie-up suggests that Mr. Benioff, who has positioned himself as a prominent voice in American business, has the industrys…