The deal should be finalized later this month.
Tyree's group has offered $25 million for the newspaper, which filed for bankruptcy on March 31, but also demanded a series of concessions from the 14 unions that represent the Sun-Times staff along with steep pay cuts.
Most of the unions agreed to the terms Wednesday, and the sale was approved fewer than 24 hours later.
"We're very pleased and very excited with this result," said Sun-Times Media Group interim CEO Jeremy Halbreich. "It could not have happened without the dedication and hard work of our employees."
The Guild of unions agreed to the concessions after two potential rival bidders dropped out of the running for the paper. Attorney and businessman Yusef Jackson, a son of the Rev. Jesse Jackson, had approached the Guild about a possible bid last week but did not follow through and, Thane Ritchie, a suburban Chicago investment manager also ditched his bid.
Last month, members of the Chicago Newspaper Guild were asked to lock in for at least three years the temporary 15 percent wage cuts imposed this spring. Other demands included wiping out seniority rules and reducing severance guarantees. Those terms were rejected.
But Sun-Times Guild members had a change of heart and approved the concessions 89-29 Wednesday night.
After that vote, Tyree said he was "encouraged immensely by the coming together.”
"Certainly not everybody is on the same page," Tyree added. But, "personally, I have a singular focus to create success for everybody. I’m looking forward to an opportunity where tears can turn into laughter and success."