In nine hours of negotiations, Philadelphia-area Catholic high school teachers and the archdiocese failed to reach a deal on a new contract Friday, with the existing pact set to expire at 12:01 a.m. Saturday.

This is the second consecutive year that negotiations between the 650-member Association of Catholic Teachers and the archdiocese went past the expiration date. At this time last year, the sides bargained through the Labor Day weekend before reaching an agreement one day before students returned to classes.

Indications are pointing toward history repeating itself next week, when the school year begins.

"We're not done yet," said Rita Schwartz, president of the Association of Catholic Teachers, "but as long as we're talking, it's good."

The sides were scheduled to return to the bargaining table on Sunday and, if necessary, Monday. Schwartz is hoping to finalize an agreement that can be brought to union members at 10 a.m. Tuesday during a general membership meeting at the Sheet Metal Workers Local 19 facility on Columbus Boulevard.

The 11,600 students at the 17 area high schools the union represents are scheduled to start classes on Wednesday.

>> READ MORE: Philly Archdiocese, high school teachers negotiate down to the wire

Negotiators were still divided over teacher pay raises and protection against ballooning health-care costs.

Currently, pay for the unionized teachers starts at $39,800; about half are veterans of at least 20 years, making around $54,480.

Last year's agreement, another in a long line of one-year deals, awarded teachers a $1,200 across-the-board raise. Their 15 percent share of medical premiums remained the same.

In a news release, the archdiocese said its proposals to this point "ensure no teacher will experience a rise in cost for health benefits."

It added that salaries for its high school teachers are consistently ranked among the highest in the nation.

The last Catholic high school teachers' strike was in 2011, when their walkout disrupted the first two weeks of the school year.

"If it's a really good contract, both of you go away a little unhappy," Schwartz said. "So, I'm hoping that we both go away a little unhappy, and that it's done."