The Plaza's deal is for five years but details were not immediately available. Workers have yet to vote on the agreement struck on Monday night, The Associated Press reported on Tuesday.
Some 50,000 Las Vegas casino workers voted to approve strike action in May. So far, MGM and Caesar's Entertainment have struck deals, averting widespread disruption ahead of the summer holidays.
The Culinary Union is discussing deals with 13 other casino-resorts on behalf of 8,000 Las Vegas workers who are without a contract.
