A union for casino-hotel workers says it has reached a tentative agreement with MGM Resorts International, covering nearly half of the 50,000 employees threatening to strike in Las Vegas.

The deal between MGM and the Culinary Workers Union Local 226 was announced by the union in a tweet late Saturday. A tentative accord between the labor union and the other big casino employer threatened by the job action, Caesars Entertainment, was reached Friday afternoon.

Some smaller operators have yet to reach agreements with the union and could still face the first citywide strike in more than 30 years.

The tentative deals with the two big operators came after thousands of bartenders, housekeepers, cocktail and food servers, porters, bellmen, cooks and other kitchen workers saw their contracts expire.