The 700 workers at the Queen Elizabeth hotel began a strike earlier Sunday but an agreement was accepted a few hours later.
Workers at the Gouverneur are expected to strike until Monday 9 a.m.
The union that represents 250 workers at the Hilton Bonaventure accepted an agreement overnight.
Since the beginning of negotiations co-ordinated by the confederation of Quebec unions, the CSN, nine of the 35 hotels accepted new collective agreements.
Michel Valiquette, the spokesman for hotel workers of the CSN, said the threats of a mass strike on Sunday served their aim and pressured employers to find new agreements faster.
Valiquette said the "domino effect" caused by the unions in 35 hotels is proving to be a successful tactic in reaching agreements with the various administrations.
Hotel workers are demanding better employment security and increased employer participation in their pension plans.
Under the new agreements, workers will receive three per cent salary increases every year. Employers will also hike their contribution to individual pension plans by two per cent based on the salary.
Montreal's Hyatt Regency has been in conflict with employers since July 25, the Holiday Inn Select Sinomonde has been on lock-out since Aug. 5, Hotel Espresso locked out its staff on Aug. 16 and Maritime Hotel workers faced locked doors in late August.
The current negotiations involve 35 unions, representing some 5,500 members who work in the hotel industry in various parts of the province.