Perzo Chief Executive David Gurle previously played key roles in developing communications software for big corporations, including banks. UBM Tech

David Gurle is on the cusp of a deal to sell his two-year-old Silicon Valley startup, Perzo Inc., to 15 of the world’s largest banks and money managers.

Yet even before executives at Goldman Sachs Group Inc. GS -0.14% zeroed in on his fledging instant-messaging company last year as a possible alternative to the chat service offered by Bloomberg LP, the 47-year-old Mr. Gurle was no stranger on Wall Street.

At previous career stops at Microsoft Corp. MSFT -0.17% , Thomson Reuters Corp. and Skype, Mr. Gurle played key roles in developing communications software for big corporations, including banks. In time, he got to know trading and technology executives at Goldman and other important clients, people familiar with the matter said.

Along the way, the France native burnished his reputation as an expert in a narrow field that had generated little buzz—that is, until Wall Street’s hunt for software that allows traders and salespeople to share messages instantly, while loosening Bloomberg’s grip on the way traders communicate, led the industry to Perzo’s Palo Alto, Calif., offices.

“He knows one thing,” Salman Ullah, a Perzo board member and a partner at Merus Capital, says jokingly. “He’s the enterprise-messaging guy,” referring to the corporate equivalent of consumer “instant message” programs offered by GoogleInc. GOOGL +0.10% “And I think other people have figured it out.”

“It’s an obscure accolade to have,” Mr. Ullah acknowledges. But it’s one of great value to large companies struggling to find ways for employees to trade instant messages as securely as they might corporate email, he says.

One of Mr. Gurle’s important allies these days is Darren Cohen, who heads Goldman’s principal strategic investments arm. Mr. Cohen has been the New York firm’s point man on the recent discussions, the people said.

Goldman and a group of top Wall Street firms are nearing an agreement to buy Perzothrough a holding company called Symphony Communication Services LLC, The Wall Street Journal reported last week. The consortium is in talks to purchase Perzo for $40 million to $50 million, and a deal could be announced as soon as this week, people familiar with the discussions said.

Mr. Gurle launched Perzo in late 2012, as companies and consumers alike were growing more concerned about privacy online. He didn’t set out to create a messaging platform just for banks, and at first Wall Street’s attention caught some of the Perzo team by surprise, a person familiar with the company said. About a year ago, Goldman had contacted the Perzo chief executive officer to explore whether Perzo’s software would fit well with technology that the Wall Street firm was developing internally, people familiar with the situation said.

Like many of its peers, Goldman has been searching for a safe way for employees to communicate instantly across different devices—between, say, a smartphone and a desktop computer, the people said. Perzo’s system promised to keep those messages secure and offered an open platform that would allow big corporate customers such as banks to customize for their use.

Goldman executives came to believe the messaging platform stood a better chance of gaining widespread acceptance on Wall Street if the industry’s biggest players also invested directly in its success.

Earlier this year, Mr. Gurle called one of his early investors to give an update on the discussions: “These guys want to talk about doing something much closer to us,” Mr. Gurle told the investor, according to a person familiar with the conversation.

The discussions grew into acquisition talks earlier this year. By September, 14 firms—from BlackRock Inc. BLK -0.70% and Citigroup Inc. C -0.44% to Citadel LLC andWells Fargo WFC +0.35% & Co.—had joined Goldman in the negotiations.

The new company would blend Perzo’s encrypted messaging software while folding in Goldman’s own back-office messaging components that would make the final product more bank-friendly, people familiar with the plans said.

The Perzo group is also in talks with one of Mr. Gurle’s old employers, Thomson Reuters, about ways they can integrate the platform into its Eikon system, the Journal reported.

“While we do not comment on rumor or speculation, Thomson Reuters believes in open, cross-industry collaboration,” Thomson Reuters said. Dow Jones, publisher of The Wall Street Journal, competes with Thomson Reuters and Bloomberg in delivering business news and information.

Mr. Ullah, who worked with Mr. Gurle at Microsoft, notes that his former colleague created a new business at the tech giant that sought to bring a messaging platform to Microsoft’s business software. Mr. Gurle would work on similar projects at Thomson Reuters and then Skype, which is now owned by Microsoft.

With the Wall Street companies’ involvement, Perzo could give financial firms’ compliance departments the ability to monitor and limit how employees chat over the messaging system, people familiar with the plans said. That is especially valuable as regulators are watching traders’ words very carefully.

Mr. Gurle “is very bright and experienced in messaging, and collaboration,” says Charles Giancarlo, a senior adviser at venture-capital firm Silver Lake. “He’s really passionate about this stuff.”

Mr. Gurle, who is expected by people familiar with the discussions to stay on with the company following its sale, declined to comment.

Mr. Giancarlo, who was a member of the Silver Lake team that acquired Skype in 2009, helped bring Mr. Gurle to that company. At past jobs, including at Thomson Reuters, Mr. Gurle would frequently attend meetings with executives at Goldman and other clients, people who worked with him said.

Former colleagues said Mr. Gurle had enjoyed the technology challenges posed by Wall Street and its focus on faster, more-secure data networks; the Perzo deal, one of them said, would mark him “coming home” to a familiar industry.

Wall Street “knows him,” Mr. Giancarlo says. “Not that they wouldn’t have trusted someone else. But without David or someone of similar stature, it probably wouldn’t get done.”