Negotiators have reached a tentative labor agreement that would cover about a quarter of the 50,000 hotel and casino workers that are threatening to strike in Las Vegas.The Culinary Workers Union Local 226 said Friday that the new five-year deal with Caesars Entertainment covers about 12,000 workers at nine casino resorts on the Las Vegas Strip. Tens of thousands of bartenders, housekeepers, bellmen and other unionized workers at 34 casino-hotels on the Strip and in downtown Las Vegas have sought a new, five-year contract since February.The current contracts expired at midnight.Ninety-nine percent of about 25,000 workers voted last week to authorize a strike. They have started signing up for strike pay, financial assistance and picketing shifts.Wages, workplace training and other issues have been the main sticking points that could still lead to the authorization of the first such strike in more than 30 years at any time starting Friday.Casinos that could still be affected by the strike, if the deal between workers and Caesars sticks, include Aria, Bellagio, Tropicana, Stratosphere and Golden Nugget.Here’s a look at the negotiations and a possible strike: The Culinary Union and companies that would be affected if workers walk off the job had bargaining sessions this week for five-year contracts. Analysts with Deutsche Bank put the likelihood of a citywide strike “as low” and said they believe negotiations could continue.”Recall, in 2013, the Culinary Union remained in negotiations with some Strip operators for several months post the June 2013 contract expiration,” analysts with the bank noted this week. “Business during this time was uninterrupted.”The last citywide strike was in 1984, costing the city and workers millions of dollars. The strike would mean no bartenders, housekeepers, cocktail and food servers, porters, bellmen, cooks and other kitchen workers at properties including Bellagio, Aria, Caesars Palace, Flamingo Las Vegas, Tropicana, Stratosphere, Golden Nugget and The D. MGM Resorts International and Caesars Entertainment operate more than half the properties that would be affected by a strike. Both companies have declined to provide details of their contingency plans.The union and hospitality experts have said the companies would use replacement workers and try to bring some in from their properties outside Las Vegas.Casino-resorts that would not be affected include Wynn Las Vegas, Encore, The Venetian and Palazzo.The strike could come as fans head to the tourist destination for the Stanley Cup Final. The union for professional hockey players in the National Hockey League sent a letter to the Culinary Union on Wednesday expressing its support for the casino workers’ “attempts to reach a fair and equitable agreement.””It is hoped that an accommodation can promptly be reached that will enable you to continue to provide the high level of service and professionalism that you have long exhibited,” National Hockey League Players’ Association executive director Donald Fehr wrote. The average hourly wage of Las Vegas Strip workers is $23, including benefits such as premium-free health care, a pension and a 401(k) retirement savings plan, and $20,000 down-payment assistance for first-time…