By Katherine Sayre

Casino operator Wynn Resorts Ltd. endured a revenue loss of nearly 95% for the quarter as the global gambling industry braces for a protracted coexistence with the coronavirus pandemic.

Wynn Resorts on Tuesday said it lost $523 million in the three months ended June 30, versus about $219 million in operating income a year earlier. Wynn's quarterly revenue fell to $85.7 million from $1.66 billion a year earlier. Wynn competitors Las Vegas Sands Corp. and MGM Resorts International recently reported revenue dives of 97% and 91%, respectively, as the industry reels from pandemic closures and depressed business and leisure travel.

U.S. casinos that reopened starting in late May and early June welcomed an initial surge of patrons thanks to pent-up demand during shutdowns that began in mid-March. But a Las Vegas Strip rebound hinges on the uncertain return of big conventions and deep-pocketed tourists arriving by airplane.

Wynn Resorts, which paid all of its 30,000 workers during the closures through the end of May, furloughed some employees last month in response to lower demand.

"There will be winners and losers that come out of this," said Wynn Chief Executive Matt Maddox. "When this is over, and we come out, we want to make sure that we have the capital available to grow, and we have the culture in place to take care of our people and our customers."

The company operates the Wynn and Encore on the Strip, Encore Boston Harbor in Massachusetts and resorts in the gambling hub of Macau. Wynn's quarterly revenue in Las Vegas was down 86%, while Macau revenue declined nearly 98%.

Wynn's Las Vegas resorts were receiving 4,000 reservations daily when they reopened with limited occupancy and other pandemic safety measures in June, but as Covid-19 cases rose sharply in California and Arizona, reservations declined by 25% after the July 4 holiday, Mr. Maddox said.

Casinos in Macau are open, but travel restrictions from China have limited the flow of tourists to the Chinese territory. Gross gambling revenue across Macau was down nearly 95% in July compared with the previous year, according to government data, the fourth straight month that declines topped 90%.

Wynn posted a net loss attributable to Wynn Resorts of about $638 million for the quarter compared with net income of $94.6 million a year earlier.

The company reported total debt of $12.78 billion and total cash of $3.8 billion as of June 30.

Write to Katherine Sayre at katherine.sayre@wsj.com