UNITED STATES.- The two largest resort operators in Las Vegas would lose more than $10 million a day combined if housekeepers, cooks and others go on strike, a possibility starting Friday, the union representing thousands of casino workers said.

The Culinary Union detailed how it thinks a one-month strike would impact MGM Resorts International and Caesars Entertainment, which operate more than half 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 casi- no operators from agreeing on new contracts.

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

Last year, more than 42.2 million people visited. But it says MGM and Caesars would see a 10 percent reduction in revenue because of the loss of group and independent travelers. A strike also could happen as fans head to Las Vegas for the Stanley Cup Final.

“Furthermore, one might assume a 10 percent worsening of operating margins due to the use of less experienced and less skilled replacements ... to keep the doors open, rooms cleaned, food cooked, and cocktails served, not to mention other factors such as the disruptions to management staff’s regular work,” the union wrote.

Using the companies’ earnings reports for the first three months of the year, the union’s estimates show a 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.

Contracts expire at midnight Thursday for 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 Pala- ce, Bellagio, Stratosphere, Treasure Island, The D and El Cortez.