Robert Bloch, the attorney for the teachers' union, said that both sides were still working out the details but that union officials were hopeful that they could present a complete agreement to the union's delegates Sunday.
"The heavy lifting is over and the framework is in place," said David Vitale, president of the Chicago Board of Education.
Union President Karen Lewis agreed, saying there were no "main sticking points right now." But she reiterated that there is also no contract yet and the strike remains in full effect.
The two sides broke up for the day but plan to reconvene this morning to work out the remaining details.
Talks between striking teachers and public schools officials had extended into the early morning hours Friday as the union and the leadership of the city's schools sought to reach a tentative deal in time for consideration by the union's roughly 700-member House of Delegates, which had been scheduled to meet Friday afternoon.
That timetable was pushed back to Sunday, but both sides expressed optimism that the delegates would vote to lift the strike Sunday, in time for school to reopen Monday.
Eventually the union's full membership of 26,000 will vote on whether to ratify the contract, but the strike vote will come first.
Both of the sides were careful not to describe the deal as a final agreement and declined to release the terms.
Schools officials said they presented a new offer that included several changes in areas of concern for the union.