Strike authorized.

Hilton Hotels Corp. had a rough week on the labor front as workers authorized strikes in Chicago, Honolulu and San Francisco. The Beverly Hills-based hotel chain posted lower-than expected second quarter earnings earlier this month, but its continued effort to reduce debt by selling off several European hotels and fitness centers, has kept investors optimistic.

Until last week, that is. Hilton stock dropped steadily and was trading at $24.30 Thursday, down from $28 back in June. This slide despite the U.S. hotels posting a 7.4 percent year-over-year room revenue increase for the week ended August 19. The survey included Marriott, Starwood and Hilton Hotels.

The workers, represented by Hotel Employees and Restaurant Employees union, voted to authorize a strike with the contract set to expire on August 31. Union spokesperson Amanda Cooper said it's not uncommon for workers to give their leadership permission to call a strike in order to strengthen their negotiators' hand at the bargaining table. Kathy Shepard, vice president of corporate communications at Hilton, emphasized that the authorization to strike does not mean workers will strike and noted that the talks are ongoing.