Another major teacher's union in the province appears to be setting the stage for a possible strike in the fall.

Ontario's English Catholic school teachers have filed for conciliation in their provincial contract talks.

Their union -- which represents about 50,000 teachers -- says it will keep bargaining with the government and trustees this summer in hopes of cutting a deal before the new school year.

Several Ontario's teachers' unions have listed class sizes, preparation time and hiring practices as sticking points in negotiations and have raised the possibility of September strikes.

Elementary teachers have been on an administrative strike since May and thousands of public high school students were out of school for weeks this spring due to strikes in the Toronto and Sudbury areas.