Cvent Holding Corp. is exploring a sale that could value the cloud-based event-software provider at upward of $4 billion, according to people familiar with the matter.

The company has attracted interest from private-equity firms including Blackstone Inc., the people said. Cvent had a market value of about $3.3 billion midday Tuesday, with the shares having lost nearly half their value from an early 2021 high.

It isn’t certain that there will be a deal. Securing loans for buyouts has become increasingly difficult, forcing private-equity firms to turn to private lenders to help fund their deals and in some cases kick in more of their own cash than they normally would.

Cvent, of Tysons, Va., provides software for in-person, virtual and other events. Its products include registration, check-in, mobile applications and event-budgeting interfaces. During the pandemic, the company shifted its focus from in-person events more toward virtual ones.

It wouldn’t be Cvent’s first time going private. Vista Equity Partners purchased the company in 2016 in a roughly $1.6 billion deal.

In 2021, the company agreed to merge with special-purpose acquisition company Dragoneer Growth Opportunities Corp. II, again giving it a public listing.

As of March, Vista still owned a roughly 80% stake, according to a Securities and Exchange Commission filing.

Private-equity deal making has been slowed by a tough financing market, a disconnect between buyers and sellers on price after equity values plummeted last year and a difficult fundraising environment in which fund backers are asking firms to return capital at a faster clip.

Vista and tech-focused buyout firm Thoma Bravo LP have been active, using more equity to get acquisitions across the finish line. Vista this month said it had agreed to buy insurance-and-property software provider Duck Creek Technologies Inc.

in a roughly $2.6 billion deal. The price represented a 46% premium using the last full trading day before the announcement.

In December, Thoma said it would purchase Coupa Software Inc. in a deal valued at $8 billion including debt.

Both Duck Creek and Cvent would represent the take-private of companies that went public and still have buyout-firm ownership. (Duck Creek went public in 2020, backed by Apax Partners.) Industry players have noted that many in the cohort of businesses that went public in recent years and still have private-equity interest are candidates for leveraged buyouts.

Write to Laura Cooper at laura.cooper@wsj.com