Hostess employed more than 850 workers in Indiana and more than 18,000 nationwide.
An Indiana University professor says mediations are usually successful, but labor disputes are the most difficult to resolve.
Hostess said it would take steps to liquidate the company if strikers did not return to work Thursday by 5 p.m.
Indiana Limestone Company workers were striking over a new contract they said could take away their seniority rights.
There has been no resolution for Indiana Limestone Company picketers, despite a meeting with a federal mediator.
Indiana Limestone Company workers have been on strike for a month and a half.
Indiana Limestone Company workers have been on strike for about two weeks.