LAS VEGAS — A union representing hospitality workers has reached a tentative agreement with four hotel-casinos in downtown Las Vegas as employees at three other properties remained poised to strike Monday when the city kicks off Super Bowl week.

By Saturday morning, the Culinary Workers Union had announced it had reached a tentative five-year contract with Binion’s, Four Queens, Fremont and Main Street that covers about 1,000 workers.

The Golden Nugget, Downtown Grand and Virgin Las Vegas near the Strip haven’t reached an agreement with the union.

The Las Vegas Strip’s three largest employers — MGM Resorts International, Caesar Entertainment and Wynn Resorts — reached deals late last year with union that covered 40,000 members, narrowly averting a historic strike.

The union then turned its attention to winning the same contract terms for works at other hotel-casinos in Las Vegas.

Since early January, the union had settled negotiations with most of those properties, including Circus Circus, Sahara Las Vegas, the Strat, Circa Resort and the El Cortez.

But after hitting a snag in negotiations with some of the remaining casinos, the union announced last week that it would go on strike if tentative contracts weren’t in place by 5 a.m. Monday for downtown casino workers at properties that hadn’t reached agreements.

The NFL’s 58th championship game is expected to bring some 330,000 people to Las Vegas this week, according to the Las Vegas Convention and Visitors Authority.

The Culinary Union is the largest in Nevada with about 60,000 members statewide. It negotiates on behalf of its members for five-year contracts.