LAS VEGAS >> The union representing thousands of Las Vegas casino workers estimated today that the two largest resort operators would lose more than $10 million a day combined if housekeepers, cooks and others go on strike at any time starting Friday.

The Culinary Union released documents explaining how it thinks a one-month strike would impact MGM Resorts International and Caesars Entertainment, which operate more than half of the properties that would be affected if 50,000 workers walk off the job.

Workers last week voted to authorize a strike as disputes over workplace training, wages and other issues have kept the union and casino operators from agreeing on new contracts.

The union conceded that it is difficult to estimate how the strike at more than 30 hotels would impact Las Vegas overall, since the last citywide labor action took place in 1984, when the city had 90,000 fewer hotel rooms and only about 12.8 million annual visitors.

But it says MGM and Caesars would see a 10 percent reduction in revenue because of the loss of group and independent travelers.

Using the companies’ earnings reports for the first three months of the year, the union’s estimates show the one-month strike could reduce MGM’s earnings before interest, taxes and other items by more than $206 million and Caesars’ by over $113 million.

The workers’ contracts expire at midnight Thursday. They are bartenders, housekeepers, cocktail and food servers, porters, bellmen, cooks and other kitchen workers at properties on the Las Vegas Strip and downtown Las Vegas, including Caesars Palace, Bellagio, Stratosphere, Treasure Island, The D and El Cortez.

Dealers are not part of the Culinary Union. Casino-resorts that would not be affected by the strike include Wynn Las Vegas, Encore, The Venetian and Palazzo.

MGM, which employees 24,000 of the workers, on Wednesday said it met with union negotiators Monday and has more talks scheduled this week. The company says it remains confident that it “can resolve the outstanding contract issues and come to an agreement that works for all sides.”

Caesars said it “expects to agree to a new 5-year contract with the Culinary Union on or about June 1 when the current contract expires.” About 12,000 of its workers are part of the negotiations.

The union said it is asking both companies for new-skill training and job opportunities as the operators continue to adopt new technology that can displace workers; an independent study to analyze the workload of housekeepers; and contract language that would protect the workers if properties are sold.

“What is going to happen to my position?” Fernando Fernandez, a guest runner at Caesars Palace, said. “I think they are going to be disappearing it because robots are going to be available to deliver everything.”

He said he wants training to fix or program the robots that he believes could eventually replace him.

The union says it has asked MGM for average wage increases of 4 percent a year for the new five-year contract. A document states the company has countered with an approximate 2.7 percent increase for each of the five years.

Meanwhile, Caesars workers are asking for an increase of 4.2 percent, and annual increases of about 4 percent thereafter. Another document shows the company has offered an approximate 2.8 percent increase for each of the five years.

The average hourly wage of union workers is $23, including benefits such as premium-free health care, a pension and a 401(k) retirement savings plan and $25,000 down-payment assistance for first-time homebuyers.