Talks are set to expire at 12:01 a.m. Monday, the Chicago Sun-Times reported.
The musicians perform at a concert Saturday night, do not perform Sunday and with Monday a typical free day, a strike could be called for Tuesday's rehearsal for concerts Thursday through Saturday with Hubbard Street Dance Chicago and guest conductor David Robertson.
"All of the plans for next week's concerts are going forward," said a CSO spokeswoman Friday, who added that management anticipated having the contract resolved before the Sunday deadline.
The CSO's annual base pay of $104,000 is higher than the Cleveland Orchestra's $100,620, but lower than Philadelphia's $105,040 and the Boston Symphony Orchestra's $108,160.
2014: The Year in Music [PHOTOS]