Union workers walked off the job at the Westin St. Francis early Wednesday morning, the third such strike at a San Francisco hotel in as many weeks.

The approximately 650 members of Unite Here! Local 2 walked off the job at 4 a.m. and are expected to stay off until early Saturday, according to the union.

The union and 61 hotels in The City have been negotiating a contract deal. The contract between the hotels and their employees ended Aug. 14.

The major sticking points in the negotiations have been health benefits, pay and the length of the contract.

Strikes have already been held at the Grand Hyatt Union Square and Palace Hotel.